This is an essential item if you are restoring, riding or racing your now vintage Yamaha XT500, SR500 or TT500 motorcycle. This is a new in the package ring set for the  XT 500 USA ( 1975, 1976, 1977, 1978, 1979, 1980, 1981) XT500 UK (1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984) TT 500 (1975-1981) and the SR500 USA (1977-81) SR 500 UK (1978-1983).  This is a standard size (STD) ring set (87mm) .  Correct for part #583-11610-00 and #583-11610-02. This has the 2 compression rings and the lower 3pc oil control ring, everything to get your piston compression back where it should be.   Get your old bike up and running again. We only sell the best! This is a top-quality aftermarket item. Good stuff if you are riding or restoring or AHRMA racing these cool bikes.