diff --git a/py/selenium/webdriver/common/by.py b/py/selenium/webdriver/common/by.py
index 56a3f96d6fbb8..65a74649f070e 100644
--- a/py/selenium/webdriver/common/by.py
+++ b/py/selenium/webdriver/common/by.py
@@ -16,7 +16,9 @@
 # under the License.
 """The By implementation."""
 
+from typing import Dict
 from typing import Literal
+from typing import Optional
 
 
 class By:
@@ -31,5 +33,19 @@ class By:
     CLASS_NAME = "class name"
     CSS_SELECTOR = "css selector"
 
+    _custom_finders: Dict[str, str] = {}
+
+    @classmethod
+    def register_custom_finder(cls, name: str, strategy: str) -> None:
+        cls._custom_finders[name] = strategy
+
+    @classmethod
+    def get_finder(cls, name: str) -> Optional[str]:
+        return cls._custom_finders.get(name) or getattr(cls, name.upper(), None)
+
+    @classmethod
+    def clear_custom_finders(cls) -> None:
+        cls._custom_finders.clear()
+
 
 ByType = Literal["id", "xpath", "link text", "partial link text", "name", "tag name", "class name", "css selector"]
diff --git a/py/selenium/webdriver/remote/locator_converter.py b/py/selenium/webdriver/remote/locator_converter.py
new file mode 100644
index 0000000000000..b43da73ef47cd
--- /dev/null
+++ b/py/selenium/webdriver/remote/locator_converter.py
@@ -0,0 +1,28 @@
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+
+class LocatorConverter:
+    def convert(self, by, value):
+        # Default conversion logic
+        if by == "id":
+            return "css selector", f'[id="{value}"]'
+        elif by == "class name":
+            return "css selector", f".{value}"
+        elif by == "name":
+            return "css selector", f'[name="{value}"]'
+        return by, value
diff --git a/py/selenium/webdriver/remote/remote_connection.py b/py/selenium/webdriver/remote/remote_connection.py
index e409d2b9c104b..0a4bde22c40d2 100644
--- a/py/selenium/webdriver/remote/remote_connection.py
+++ b/py/selenium/webdriver/remote/remote_connection.py
@@ -143,6 +143,14 @@ class RemoteConnection:
     )
     _ca_certs = os.getenv("REQUESTS_CA_BUNDLE") if "REQUESTS_CA_BUNDLE" in os.environ else certifi.where()
 
+    system = platform.system().lower()
+    if system == "darwin":
+        system = "mac"
+
+    # Class variables for headers
+    extra_headers = None
+    user_agent = f"selenium/{__version__} (python {system})"
+
     @classmethod
     def get_timeout(cls):
         """:Returns:
@@ -196,14 +204,10 @@ def get_remote_connection_headers(cls, parsed_url, keep_alive=False):
          - keep_alive (Boolean) - Is this a keep-alive connection (default: False)
         """
 
-        system = platform.system().lower()
-        if system == "darwin":
-            system = "mac"
-
         headers = {
             "Accept": "application/json",
             "Content-Type": "application/json;charset=UTF-8",
-            "User-Agent": f"selenium/{__version__} (python {system})",
+            "User-Agent": cls.user_agent,
         }
 
         if parsed_url.username:
@@ -213,6 +217,9 @@ def get_remote_connection_headers(cls, parsed_url, keep_alive=False):
         if keep_alive:
             headers.update({"Connection": "keep-alive"})
 
+        if cls.extra_headers:
+            headers.update(cls.extra_headers)
+
         return headers
 
     def _get_proxy_url(self):
@@ -236,7 +243,12 @@ def _separate_http_proxy_auth(self):
 
     def _get_connection_manager(self):
         pool_manager_init_args = {"timeout": self.get_timeout()}
-        if self._ca_certs:
+        pool_manager_init_args.update(self._init_args_for_pool_manager.get("init_args_for_pool_manager", {}))
+
+        if self._ignore_certificates:
+            pool_manager_init_args["cert_reqs"] = "CERT_NONE"
+            urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
+        elif self._ca_certs:
             pool_manager_init_args["cert_reqs"] = "CERT_REQUIRED"
             pool_manager_init_args["ca_certs"] = self._ca_certs
 
@@ -252,9 +264,18 @@ def _get_connection_manager(self):
 
         return urllib3.PoolManager(**pool_manager_init_args)
 
-    def __init__(self, remote_server_addr: str, keep_alive: bool = False, ignore_proxy: bool = False):
+    def __init__(
+        self,
+        remote_server_addr: str,
+        keep_alive: bool = False,
+        ignore_proxy: bool = False,
+        ignore_certificates: bool = False,
+        init_args_for_pool_manager: dict = None,
+    ):
         self.keep_alive = keep_alive
         self._url = remote_server_addr
+        self._ignore_certificates = ignore_certificates
+        self._init_args_for_pool_manager = init_args_for_pool_manager or {}
 
         # Env var NO_PROXY will override this part of the code
         _no_proxy = os.environ.get("no_proxy", os.environ.get("NO_PROXY"))
@@ -280,6 +301,16 @@ def __init__(self, remote_server_addr: str, keep_alive: bool = False, ignore_pro
             self._conn = self._get_connection_manager()
         self._commands = remote_commands
 
+    extra_commands = {}
+
+    def add_command(self, name, method, url):
+        """Register a new command."""
+        self._commands[name] = (method, url)
+
+    def get_command(self, name: str):
+        """Retrieve a command if it exists."""
+        return self._commands.get(name)
+
     def execute(self, command, params):
         """Send a command to the remote server.
 
@@ -291,7 +322,7 @@ def execute(self, command, params):
          - params - A dictionary of named parameters to send with the command as
            its JSON payload.
         """
-        command_info = self._commands[command]
+        command_info = self._commands.get(command) or self.extra_commands.get(command)
         assert command_info is not None, f"Unrecognised command {command}"
         path_string = command_info[1]
         path = string.Template(path_string).substitute(params)
diff --git a/py/selenium/webdriver/remote/webdriver.py b/py/selenium/webdriver/remote/webdriver.py
index 41c4645bdc686..8ef6292012089 100644
--- a/py/selenium/webdriver/remote/webdriver.py
+++ b/py/selenium/webdriver/remote/webdriver.py
@@ -58,6 +58,7 @@
 from .errorhandler import ErrorHandler
 from .file_detector import FileDetector
 from .file_detector import LocalFileDetector
+from .locator_converter import LocatorConverter
 from .mobile import Mobile
 from .remote_connection import RemoteConnection
 from .script_key import ScriptKey
@@ -171,6 +172,8 @@ def __init__(
         keep_alive: bool = True,
         file_detector: Optional[FileDetector] = None,
         options: Optional[Union[BaseOptions, List[BaseOptions]]] = None,
+        locator_converter: Optional[LocatorConverter] = None,
+        web_element_cls: Optional[type] = None,
     ) -> None:
         """Create a new driver that will issue commands using the wire
         protocol.
@@ -183,6 +186,8 @@ def __init__(
          - file_detector - Pass custom file detector object during instantiation. If None,
              then default LocalFileDetector() will be used.
          - options - instance of a driver options.Options class
+         - locator_converter - Custom locator converter to use. Defaults to None.
+         - web_element_cls - Custom class to use for web elements. Defaults to WebElement.
         """
 
         if isinstance(options, list):
@@ -207,6 +212,8 @@ def __init__(
         self._switch_to = SwitchTo(self)
         self._mobile = Mobile(self)
         self.file_detector = file_detector or LocalFileDetector()
+        self.locator_converter = locator_converter or LocatorConverter()
+        self._web_element_cls = web_element_cls or self._web_element_cls
         self._authenticator_id = None
         self.start_client()
         self.start_session(capabilities)
@@ -729,22 +736,14 @@ def find_element(self, by=By.ID, value: Optional[str] = None) -> WebElement:
 
         :rtype: WebElement
         """
+        by, value = self.locator_converter.convert(by, value)
+
         if isinstance(by, RelativeBy):
             elements = self.find_elements(by=by, value=value)
             if not elements:
                 raise NoSuchElementException(f"Cannot locate relative element with: {by.root}")
             return elements[0]
 
-        if by == By.ID:
-            by = By.CSS_SELECTOR
-            value = f'[id="{value}"]'
-        elif by == By.CLASS_NAME:
-            by = By.CSS_SELECTOR
-            value = f".{value}"
-        elif by == By.NAME:
-            by = By.CSS_SELECTOR
-            value = f'[name="{value}"]'
-
         return self.execute(Command.FIND_ELEMENT, {"using": by, "value": value})["value"]
 
     def find_elements(self, by=By.ID, value: Optional[str] = None) -> List[WebElement]:
@@ -757,22 +756,14 @@ def find_elements(self, by=By.ID, value: Optional[str] = None) -> List[WebElemen
 
         :rtype: list of WebElement
         """
+        by, value = self.locator_converter.convert(by, value)
+
         if isinstance(by, RelativeBy):
             _pkg = ".".join(__name__.split(".")[:-1])
             raw_function = pkgutil.get_data(_pkg, "findElements.js").decode("utf8")
             find_element_js = f"/* findElements */return ({raw_function}).apply(null, arguments);"
             return self.execute_script(find_element_js, by.to_dict())
 
-        if by == By.ID:
-            by = By.CSS_SELECTOR
-            value = f'[id="{value}"]'
-        elif by == By.CLASS_NAME:
-            by = By.CSS_SELECTOR
-            value = f".{value}"
-        elif by == By.NAME:
-            by = By.CSS_SELECTOR
-            value = f'[name="{value}"]'
-
         # Return empty list if driver returns null
         # See https://github.com/SeleniumHQ/selenium/issues/4555
         return self.execute(Command.FIND_ELEMENTS, {"using": by, "value": value})["value"] or []
diff --git a/py/selenium/webdriver/remote/webelement.py b/py/selenium/webdriver/remote/webelement.py
index ef60757294caa..08c772eaad56e 100644
--- a/py/selenium/webdriver/remote/webelement.py
+++ b/py/selenium/webdriver/remote/webelement.py
@@ -404,16 +404,7 @@ def find_element(self, by=By.ID, value=None) -> WebElement:
 
         :rtype: WebElement
         """
-        if by == By.ID:
-            by = By.CSS_SELECTOR
-            value = f'[id="{value}"]'
-        elif by == By.CLASS_NAME:
-            by = By.CSS_SELECTOR
-            value = f".{value}"
-        elif by == By.NAME:
-            by = By.CSS_SELECTOR
-            value = f'[name="{value}"]'
-
+        by, value = self._parent.locator_converter.convert(by, value)
         return self._execute(Command.FIND_CHILD_ELEMENT, {"using": by, "value": value})["value"]
 
     def find_elements(self, by=By.ID, value=None) -> List[WebElement]:
@@ -426,16 +417,7 @@ def find_elements(self, by=By.ID, value=None) -> List[WebElement]:
 
         :rtype: list of WebElement
         """
-        if by == By.ID:
-            by = By.CSS_SELECTOR
-            value = f'[id="{value}"]'
-        elif by == By.CLASS_NAME:
-            by = By.CSS_SELECTOR
-            value = f".{value}"
-        elif by == By.NAME:
-            by = By.CSS_SELECTOR
-            value = f'[name="{value}"]'
-
+        by, value = self._parent.locator_converter.convert(by, value)
         return self._execute(Command.FIND_CHILD_ELEMENTS, {"using": by, "value": value})["value"]
 
     def __hash__(self) -> int:
diff --git a/py/test/selenium/webdriver/common/driver_element_finding_tests.py b/py/test/selenium/webdriver/common/driver_element_finding_tests.py
index 2578ac2f57861..205edb92e1f88 100644
--- a/py/test/selenium/webdriver/common/driver_element_finding_tests.py
+++ b/py/test/selenium/webdriver/common/driver_element_finding_tests.py
@@ -715,3 +715,21 @@ def test_should_not_be_able_to_find_an_element_on_a_blank_page(driver, pages):
     driver.get("about:blank")
     with pytest.raises(NoSuchElementException):
         driver.find_element(By.TAG_NAME, "a")
+
+
+# custom finders tests
+
+
+def test_register_and_get_custom_finder():
+    By.register_custom_finder("custom", "custom strategy")
+    assert By.get_finder("custom") == "custom strategy"
+
+
+def test_get_nonexistent_finder():
+    assert By.get_finder("nonexistent") is None
+
+
+def test_clear_custom_finders():
+    By.register_custom_finder("custom", "custom strategy")
+    By.clear_custom_finders()
+    assert By.get_finder("custom") is None
diff --git a/py/test/selenium/webdriver/remote/custom_element_tests.py b/py/test/selenium/webdriver/remote/custom_element_tests.py
new file mode 100644
index 0000000000000..3fccb52ad3119
--- /dev/null
+++ b/py/test/selenium/webdriver/remote/custom_element_tests.py
@@ -0,0 +1,50 @@
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from selenium.webdriver.common.by import By
+from selenium.webdriver.remote.webelement import WebElement
+
+
+# Custom element class
+class MyCustomElement(WebElement):
+    def custom_method(self):
+        return "Custom element method"
+
+
+def test_find_element_with_custom_class(driver, pages):
+    """Test to ensure custom element class is used for a single element."""
+    driver._web_element_cls = MyCustomElement
+    pages.load("simpleTest.html")
+    element = driver.find_element(By.TAG_NAME, "body")
+    assert isinstance(element, MyCustomElement)
+    assert element.custom_method() == "Custom element method"
+
+
+def test_find_elements_with_custom_class(driver, pages):
+    """Test to ensure custom element class is used for multiple elements."""
+    driver._web_element_cls = MyCustomElement
+    pages.load("simpleTest.html")
+    elements = driver.find_elements(By.TAG_NAME, "div")
+    assert all(isinstance(el, MyCustomElement) for el in elements)
+    assert all(el.custom_method() == "Custom element method" for el in elements)
+
+
+def test_default_element_class(driver, pages):
+    """Test to ensure default WebElement class is used."""
+    pages.load("simpleTest.html")
+    element = driver.find_element(By.TAG_NAME, "body")
+    assert isinstance(element, WebElement)
+    assert not hasattr(element, "custom_method")
diff --git a/py/test/selenium/webdriver/remote/remote_custom_locator_tests.py b/py/test/selenium/webdriver/remote/remote_custom_locator_tests.py
new file mode 100644
index 0000000000000..e235f2ee2e999
--- /dev/null
+++ b/py/test/selenium/webdriver/remote/remote_custom_locator_tests.py
@@ -0,0 +1,40 @@
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from selenium.webdriver.remote.locator_converter import LocatorConverter
+
+
+class CustomLocatorConverter(LocatorConverter):
+    def convert(self, by, value):
+        # Custom conversion logic
+        if by == "custom":
+            return "css selector", f'[custom-attr="{value}"]'
+        return super().convert(by, value)
+
+
+def test_find_element_with_custom_locator(driver):
+    driver.get("data:text/html,<div custom-attr='example'>Test</div>")
+    element = driver.find_element("custom", "example")
+    assert element is not None
+    assert element.text == "Test"
+
+
+def test_find_elements_with_custom_locator(driver):
+    driver.get("data:text/html,<div custom-attr='example'>Test1</div><div custom-attr='example'>Test2</div>")
+    elements = driver.find_elements("custom", "example")
+    assert len(elements) == 2
+    assert elements[0].text == "Test1"
+    assert elements[1].text == "Test2"
diff --git a/py/test/unit/selenium/webdriver/remote/remote_connection_tests.py b/py/test/unit/selenium/webdriver/remote/remote_connection_tests.py
index 2c798365d85f5..260214e5c918d 100644
--- a/py/test/unit/selenium/webdriver/remote/remote_connection_tests.py
+++ b/py/test/unit/selenium/webdriver/remote/remote_connection_tests.py
@@ -15,6 +15,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
+from unittest.mock import patch
 from urllib import parse
 
 import pytest
@@ -24,6 +25,31 @@
 from selenium.webdriver.remote.remote_connection import RemoteConnection
 
 
+@pytest.fixture
+def remote_connection():
+    """Fixture to create a RemoteConnection instance."""
+    return RemoteConnection("http://localhost:4444")
+
+
+def test_add_command(remote_connection):
+    """Test adding a custom command to the connection."""
+    remote_connection.add_command("CUSTOM_COMMAND", "PUT", "/session/$sessionId/custom")
+    assert remote_connection.get_command("CUSTOM_COMMAND") == ("PUT", "/session/$sessionId/custom")
+
+
+@patch("selenium.webdriver.remote.remote_connection.RemoteConnection._request")
+def test_execute_custom_command(mock_request, remote_connection):
+    """Test executing a custom command through the connection."""
+    remote_connection.add_command("CUSTOM_COMMAND", "PUT", "/session/$sessionId/custom")
+    mock_request.return_value = {"status": 200, "value": "OK"}
+
+    params = {"sessionId": "12345"}
+    response = remote_connection.execute("CUSTOM_COMMAND", params)
+
+    mock_request.assert_called_once_with("PUT", "http://localhost:4444/session/12345/custom", body="{}")
+    assert response == {"status": 200, "value": "OK"}
+
+
 def test_get_remote_connection_headers_defaults():
     url = "http://remote"
     headers = RemoteConnection.get_remote_connection_headers(parse.urlparse(url))
@@ -32,7 +58,7 @@ def test_get_remote_connection_headers_defaults():
     assert headers.get("Accept") == "application/json"
     assert headers.get("Content-Type") == "application/json;charset=UTF-8"
     assert headers.get("User-Agent").startswith(f"selenium/{__version__} (python ")
-    assert headers.get("User-Agent").split(" ")[-1] in {"windows)", "mac)", "linux)"}
+    assert headers.get("User-Agent").split(" ")[-1] in {"windows)", "mac)", "linux)", "mac", "windows", "linux"}
 
 
 def test_get_remote_connection_headers_adds_auth_header_if_pass():
@@ -239,3 +265,52 @@ def mock_no_proxy_settings(monkeypatch):
     monkeypatch.setenv("http_proxy", http_proxy)
     monkeypatch.setenv("no_proxy", "65.253.214.253,localhost,127.0.0.1,*zyz.xx,::1")
     monkeypatch.setenv("NO_PROXY", "65.253.214.253,localhost,127.0.0.1,*zyz.xx,::1,127.0.0.0/8")
+
+
+@patch("selenium.webdriver.remote.remote_connection.RemoteConnection.get_remote_connection_headers")
+def test_override_user_agent_in_headers(mock_get_remote_connection_headers, remote_connection):
+    RemoteConnection.user_agent = "custom-agent/1.0 (python 3.8)"
+
+    mock_get_remote_connection_headers.return_value = {
+        "Accept": "application/json",
+        "Content-Type": "application/json;charset=UTF-8",
+        "User-Agent": "custom-agent/1.0 (python 3.8)",
+    }
+
+    headers = RemoteConnection.get_remote_connection_headers(parse.urlparse("http://remote"))
+
+    assert headers.get("User-Agent") == "custom-agent/1.0 (python 3.8)"
+    assert headers.get("Accept") == "application/json"
+    assert headers.get("Content-Type") == "application/json;charset=UTF-8"
+
+
+@patch("selenium.webdriver.remote.remote_connection.RemoteConnection._request")
+def test_register_extra_headers(mock_request, remote_connection):
+    RemoteConnection.extra_headers = {"Foo": "bar"}
+
+    mock_request.return_value = {"status": 200, "value": "OK"}
+    remote_connection.execute("newSession", {})
+
+    mock_request.assert_called_once_with("POST", "http://localhost:4444/session", body="{}")
+    headers = RemoteConnection.get_remote_connection_headers(parse.urlparse("http://localhost:4444"), False)
+    assert headers["Foo"] == "bar"
+
+
+def test_get_connection_manager_ignores_certificates(monkeypatch):
+    monkeypatch.setattr(RemoteConnection, "get_timeout", lambda _: 10)
+    remote_connection = RemoteConnection("http://remote", ignore_certificates=True)
+    conn = remote_connection._get_connection_manager()
+
+    assert conn.connection_pool_kw["timeout"] == 10
+    assert conn.connection_pool_kw["cert_reqs"] == "CERT_NONE"
+    assert isinstance(conn, urllib3.PoolManager)
+
+
+def test_get_connection_manager_with_custom_args():
+    custom_args = {"init_args_for_pool_manager": {"retries": 3, "block": True}}
+    remote_connection = RemoteConnection("http://remote", keep_alive=False, init_args_for_pool_manager=custom_args)
+    conn = remote_connection._get_connection_manager()
+
+    assert isinstance(conn, urllib3.PoolManager)
+    assert conn.connection_pool_kw["retries"] == 3
+    assert conn.connection_pool_kw["block"] is True