DRP's design addresses being able to place a return sump under the factory sending unit in the tank. This is the sweet spot for all fuel levels. Having it forward or in the back of the sending unit can cause issues with low fuel during those rowdy moments stabbing on the throttle or getting on the brakes hard. Only one hole to drill in the tank means fewer chances for a leak. Our sump ring also has more surface area than the competitors, so you have a more positive sealing surface. The return sump uses the same size mounting hole (3.25") as our non-return sump. Feel like upgrading? It will bolt right in place.