The CH Throttle Quadrant USB Hardware driver is a software component required for the CH Products Throttle Quadrant to function properly on a Windows-based PC. The Throttle Quadrant is a piece of flight simulation hardware used to control throttle, mixture, propeller pitch, or other engine controls in virtual flight simulators like Microsoft Flight Simulator, X-Plane, or others. The USB driver allows the operating system to communicate with the Throttle Quadrant and make its buttons, sliders, and rotary knobs operational.