Camshaft - Single Cam - Stage 2 - Yamaha Computer Numerical Control (CNC) from 8620 billet steel and case harden, Designed and dyno proven in the USA, Engineered by using valvetrain software, Adds a 5%-10% power gain, Select cams feature Hot Cams Improved Throttle Design (I.T.R.) technology; these cams improve throttle response throughout the entire rpm range while providing excellent power gains through the mid-range and top-end, Designed for mid to top end gains., Engineered to be drop in cams that use stock valve springs (unless otherwise noted).