The Skunk2 Composite Velocity Stack utilizes race proven technology and is engineered to optimize air flow while maximizing velocity for your induction system. Injection-molded from 30% Glass Filled Nylon 6 imparts high impact strength with low thermal conductivity to significantly reduce heat soak and air intake temperatures. The design also incorporates dimples on the entry surface to extend the boundary layer into the mouth. This increases the effective cross sectional area thus enabling higher total mass air flow compared to standard velocity stacks. The Skunk2 Composite Velocity Stack features a 3.5 in. in. connection to fit various style of intake pipes or tubing. The Skunk2 composite velocity stacks are a great addition for any application looking to maximize air flow. Skunk2 Composite Velocity Stacks are a great addition for Naturally Aspirated and Turbo applications.