Serrated/Helix Design: The Serrated/Helix design creates air turbulence in the intake manifold. This turbulence increases the air pressure in the combustion chamber resulting in increased horsepower, torque and improved throttle response. The Serrated/Helix combination design also reduces intake whistle that occurs with other helix only designs. (US PAT 07055513). 6061-T6 Billet Aluminum Construction: All Silver Bullet Throttle Body Spacers are precision machined from 6061-T6 billet aluminum for lightweight, high strength and perfect fit and finish. High Strength Silicone: This double hump coupling is constructed of high temperature silicone which meets or exceeds SAEJ20 Standards. Installation Is A Snap: This Silver Bullet throttle body spacer uses all factory mounting locations and a gasket providing stability and a hassle-free installation. Emissions Disclaimer: This product does not require a CARB EO# (Vehicle does not exist in U.S.). Will work with aFe's Momentum GT intakes (P/N: 51/54/75-76104).