This is a set of new ignition contact points for the 1973 1974 1975 1976 1977 1978 Yamaha TX500 and XS500 Motorcycles. This is 1 left side and 1 right side!  This is an essential part of any tune-up. Hard to find..here you go!  Top quality aftermarket set. These are correct replacement for the left and right side corresponding with Yamaha part #: 371-81622-10-00, 371-81621-10-00.