S&S Cycle Cam Chain Tensioner For Harley M8 Features: Precision-machined from 6061 billet aluminum Larger diameter piston and tighter tolerance fit of the shoe in the body provide improved stability, no more rocking shoes Thicker pad for longer wear between service Direct chain oiling Chain oiling feature provides oil to the chain rails right before crossing the tensioner for increased lubrication and greater cooling Made in the USA