Installed in your throttle body’s Venturi tube, the precision-engineered sleeve reduces the diameter and accelerates the velocity of your air-fuel mix. With a thinner butterfly valve and less obstructive shaft, you have faster, more even throttle response through the low and mid-range of the engine. If you prefer a better top-end throttle response, use the larger butterfly valve without the sleeve. Features Get faster, smoother throttle response Eliminate high-end flow loss by lowering flow restriction Install/remove without damaging the OEM throttle body Count on maintenance-free reliability after installation