diff --git a/commands2/__init__.py b/commands2/__init__.py
index 1c243a7..2b64950 100644
--- a/commands2/__init__.py
+++ b/commands2/__init__.py
@@ -2,6 +2,7 @@
 
 from . import button
 from . import cmd
+from . import typing
 
 from .commandscheduler import CommandScheduler
 from .conditionalcommand import ConditionalCommand
diff --git a/commands2/profiledpidcommand.py b/commands2/profiledpidcommand.py
index 232eabf..d7ce298 100644
--- a/commands2/profiledpidcommand.py
+++ b/commands2/profiledpidcommand.py
@@ -5,14 +5,19 @@
 # the WPILib BSD license file in the root directory of this project.
 #
 
-from typing import Any, Callable, Generic, Union
+from typing import Any, Generic
 
 from wpimath.controller import ProfiledPIDController, ProfiledPIDControllerRadians
 from wpimath.trajectory import TrapezoidProfile, TrapezoidProfileRadians
 
 from .command import Command
 from .subsystem import Subsystem
-from .typing import TProfiledPIDController, UseOutputFunction
+from .typing import (
+    FloatOrFloatSupplier,
+    FloatSupplier,
+    TProfiledPIDController,
+    UseOutputFunction,
+)
 
 
 class ProfiledPIDCommand(Command, Generic[TProfiledPIDController]):
@@ -26,8 +31,8 @@ class ProfiledPIDCommand(Command, Generic[TProfiledPIDController]):
     def __init__(
         self,
         controller: TProfiledPIDController,
-        measurementSource: Callable[[], float],
-        goalSource: Union[float, Callable[[], float]],
+        measurementSource: FloatSupplier,
+        goalSource: FloatOrFloatSupplier,
         useOutput: UseOutputFunction,
         *requirements: Subsystem,
     ):
diff --git a/commands2/profiledpidsubsystem.py b/commands2/profiledpidsubsystem.py
index 2e970ba..4a05baa 100644
--- a/commands2/profiledpidsubsystem.py
+++ b/commands2/profiledpidsubsystem.py
@@ -25,7 +25,13 @@ def __init__(
         controller: TProfiledPIDController,
         initial_position: float = 0,
     ):
-        """Creates a new PIDSubsystem."""
+        """
+        Creates a new Profiled PID Subsystem using the provided PID Controller
+
+        :param controller:        the controller that controls the output
+        :param initial_position:  the initial value of the process variable
+
+        """
         super().__init__()
         self._controller: TProfiledPIDController = controller
         self._enabled = False
@@ -46,15 +52,11 @@ def getController(
         return self._controller
 
     def setGoal(self, goal):
-        """
-        Sets the goal state for the subsystem.
-        """
+        """Sets the goal state for the subsystem."""
         self._controller.setGoal(goal)
 
     def useOutput(self, output: float, setpoint: TTrapezoidProfileState):
-        """
-        Uses the output from the controller object.
-        """
+        """Uses the output from the controller object."""
         raise NotImplementedError(f"{self.__class__} must implement useOutput")
 
     def getMeasurement(self) -> float:
@@ -75,7 +77,5 @@ def disable(self):
         self.useOutput(0, TrapezoidProfile.State())
 
     def isEnabled(self) -> bool:
-        """
-        Returns whether the controller is enabled.
-        """
+        """Returns whether the controller is enabled."""
         return self._enabled
diff --git a/commands2/typing.py b/commands2/typing.py
index 357b928..6168330 100644
--- a/commands2/typing.py
+++ b/commands2/typing.py
@@ -1,8 +1,10 @@
-from typing import Protocol, TypeVar
+from typing import Callable, Protocol, TypeVar, Union
 
+from typing_extensions import TypeAlias
 from wpimath.controller import ProfiledPIDController, ProfiledPIDControllerRadians
 from wpimath.trajectory import TrapezoidProfile, TrapezoidProfileRadians
 
+# Generic Types
 TProfiledPIDController = TypeVar(
     "TProfiledPIDController", ProfiledPIDControllerRadians, ProfiledPIDController
 )
@@ -13,10 +15,16 @@
 )
 
 
+# Protocols - Structural Typing
 class UseOutputFunction(Protocol):
 
-    def __init__(self): ...
+    def __init__(self, *args, **kwargs) -> None: ...
 
     def __call__(self, t: float, u: TTrapezoidProfileState) -> None: ...
 
     def accept(self, t: float, u: TTrapezoidProfileState) -> None: ...
+
+
+# Type Aliases
+FloatSupplier: TypeAlias = Callable[[], float]
+FloatOrFloatSupplier: TypeAlias = Union[float, Callable[[], float]]