Rotary Corp brand aftermarket product. Drive Belt Idler Pulley replaces 583512101. Old number 532436812. Flat Idler pulley for ground drive system. Fits models CT153, CT154, CTH163T, CTH174, CTH184, CTH194, TC138, TC142, TC342. Fits Jonsered and models LT2316CM, LT2317CM, LT2318CM, LT232323CM and many more. Refer to your parts manual for correct fitment.