Skunk2 designs, develops and tests all valvetrain components in-house to ensure the highest quality and greatest performance gains. During development, all valvetrain components are tested in engines both on the dyno and on the road. Skunk2 valvetrain components provide exceptional performance, reliability, and quality. Skunk2 Pro-Series titanium retainers are CNC-machined in-house from certified medical grade titanium that is milled in the USA. Skunk2 retainers are designed to significantly reduce overall valvetrain mass and are machined to extremely close tolerances in order to ensure properly installed spring heights and pressures. Skunk2 has been supplying titanium retainers to professional racecars and street cars for nearly a decade, and are used on all Skunk2 race and project cars.