Tachometer gear drive and housing for Honda 1971-1973 CB500, CB550 1974-1978, in addition the HOUSING ONLY will fit 1979-1982 Honda CB650...AGAIN the gear drive itself is compatible only with the CB500's and CB550's, the housing fits all including the CB650's. Nice used condition, includes hardware and "O" rings as shown. Any questions please ask and I will respond quickly. Thanks for looking