... :2000 3.different needs from different customers MODELS AVAILABLE:KOMATSU,CATERPILLAR, HITACHI ,KATO, KOBELCO, MITUBISHI:D20,D21,D30,D31, ... ,K904E,K905/A/B,K906,k907k910,k912,k914,k935.....,CATERPILLAR:D4D/E,D4DLGP/SA,D6C/LGP/SA,D6D/LGP/ ... of excavators, bulldozers and loaders, such as undercarriage track roller,carrier roller, idler, sprocket, track link/chain, and hydraulic breaker, piston, chisel, ...