Power Take-Off (PTO) units transfer engine rotational power to auxiliary equipment mounted on a vehicle. Primarily used in commercial and agricultural applications, PTOs are typically connected to a transmission output shaft or directly to the engine flywheel housing. Designs incorporate a gear-based or electromagnetic clutch mechanism for controlled engagement and disengagement of the auxiliary drive. Output configurations include direct drive, overrun, and hydraulic engagement types, varying by application demand. Common auxiliary equipment driven includes hydraulic pumps, air compressors, and winches, demanding robust construction and precise alignment for reliable operation.