Our Fuel Tank Sump with Built-In Fuel Return provides you with a perfect option to maximize fuel delivery, and customization when installing your aftermarket fuel system. Avoid the common 1/4 tank issues. used with fuel systems such as AirDog, FASS and many others. Our sump features a one-hole design that only requires drilling a single 3" hole for installation. A machined groove for the o-ring gasket ensures a leak-free seal, and the inner-ring is designed to fit into the bottom of the tank without requiring you to remove it from the truck.