Genuine OEM Toyota Tensioner Assembly, part number 1662024021. This component is part of the V-ribbed belt system, functioning to maintain the correct tension on the belt. Proper belt tension is crucial for the reliable operation of accessories driven by the engine, such as the alternator, power steering pump, and air conditioning compressor. The assembly includes the tensioner pulley and its mounting mechanism. Genuine OEM parts are manufactured to exact specifications, ensuring proper fit, function, and longevity for the belt drive system.