Attwood Shower Sump System 500 GPH or 750 GPH models available. This Attwood sump system provides reliable performance, larger capacity, and simpler installation and maintenance. Sump box features include: an air vent to prevent air locks. Slotted mounting feet which allow for quick installation and removal. Straight mesh filter which allows for easy removal and cleaning. Inlets are routed directly into the sump box instead of through a shared manifold. Attwood system allows additional inlets to be added to the left, right and back side of the sump box through the use of through hulls. Water is pumped out with Attwood's sahara pump with self-contained float switch. New lid easily snaps on and off and includes a gasket to seal the sump box against overflow.