Weight: 0.17Hastings ring sets to fit S&S, Rev Tech, MID-USA and many other 3 5/8" Big Bore pistons. Each set has a 5/64" thick moly top compression ring, 5/64" thick 2nd ring and 3/16" thick bottom ring. Sold in a set for one piston. Fits Knucklehead, Panhead and Shovelhead engines All Years.Piston ring set. +.030" OS.By: HASTINGS MANUFACTURING COMPANY