1,Bimetal bush 2,PTFE with lead 0.01-0.03mm 3 ... or can not add oil, it need not maintain or reduce maintain during usage.2,Fine antifriction, small friction coeffiction, ... that not hardening and tempering could be used, accordingly reduce some difficulties about maching accessories8,Thin wall structure, light ... micro-machine, automobile, motorcycle, agriculture machine Benz OM314 CONROD BUSH 55-8155