The SerratedHelix design creates air turbulence in the intake manifold to increase air pressure in the combustion chamber resulting in increased horsepower, torque and improved throttle response. The SerratedHelix combination design also reduces intake whistle that occurs with other helix only designs. (US PAT 07055513). Made from 6061 - T6 Billet Aluminum aFe Silver Bullet Throttle Body Spacers are precision machined for lightweight, high strength and perfect fit. These spacers come with gaskets and use all factory mounting locations for a hassle - free installation.