Black hard anodized aluminum construction; sold in a set of 2. Stock tappet guides / anti-rotation devices are made of plastic and could allow tappets to twist in heavy stress; high RPM situations. These S&S tappet cuffs are precision CNC machined from billet aluminum that is black hard anodized. They offer superior strength; stability and perfect alignment in all circumstances without obstructing the vertical tappet movement in any way. Individually marked for front or rear use. An easy performance upgrade when doing a tappet or cam change. This set is an upgrade for the OEM 17900035 & 17900034 ”anti-rotation devices”. Note: Due to variations between cam and tappet manufacturers; be sure to check tappet to tappet cuff clearance.