This a T-RAIL END MOUNT with idler pulley for a chamberlin,liftmaster or sears craftsman. chain drive model that uses a FULL CHAIN it includes the nuts bolts to assemble #12B0411. The end mount connects the t-rail to the wall mount (sold seperately). This item is used it has be cleaned and checked for useability and wear. It is in excellent condition. (676)A17,b5
