Skunk2_s industry-leading Titanium Retainers for Honda_s F-series S2000 engines are designed to significantly reduce valvetrain mass, resulting in more horsepower and improved valvetrain stability. Unlink other retainers, Skunk2 Titanium Retainers feature radius-cut edges for additional rocker arm clearance and reduced weight, strategically positioned lightening grooves, and reduced overall heights for better valve seal clearance and even further weight reduction. All Skunk2 Titanium Retainers are manufactured using the latest 3D CAD (Computer Aided Design) and FEA (Finite Element Analysis) to ensure that each is optimized for strength as well as for reduced weight. Skunk2 engineers then test and prove their designs on the engine dyno as well as the race track. Once approved for manufacturing, only medical-grade titanium that_s been ultrasonically inspected and certified is used. Following CNC machining, each retainer is then individually inspected to ensure proper hole diameter, taper, and that each are free from machining defects to ensure proper installed valve spring heights and pressures. Finally, each Titanium Retainer is serialized for your protection, including valuable information, like material batch specifics as well as production and inspection dates. Note: 42 percent lighter than OEM steel retainers. Pair with Tuner Series or Pro Series Valve Springs for the ultimate valvetrain.