... Long lifespan 3, Precision-machined 4, Professional manufacturer 1. 3rd or 4th synchrotron assembly for transit Transmission 1. countershaft 5th ... steel,tempered steel,cast iron,aluminum,copper,brass 3.OEM: 3rd or 4th synchrotron assembly transit Transmission . 4. Professional ... welcome to visit our factory for business negotiation ! 3rd or 4th synchrotron assembly for Transit Transmission