Billet 4" Turbo Inlet Guard – Velocity Stack Bellmouth Adapter Optimized Fitment for Turbochargers Enhance your turbo system with this precision-machined billet aluminum velocity stack. Designed for a perfect fit on turbos, this 4" inlet guard features a smooth, bellmouth-style taper that improves airflow efficiency by minimizing turbulence and reducing boundary layer separation. CNC-machined from high-grade billet aluminum Smooth, funnel-shaped design maximizes volumetric flow Hex-pattern filter helps block larger debris from entering your turbo or engine Compatible with 4" turbo and naturally aspirated intake applications Includes set screw and removable thread sealer for secure installation Ideal for performance builds requiring both protection and unrestricted airflow.