Rule Non-Automatic 1100 GPH 12 Volt Bilge Pump 27DA Rule Non-Automatic Bilge Pumps deliver ultimate pumping performance in an easy-to-install pump. It has an optimized impeller to provide greater flow at the same amperage. This bilge pump features back flow prevention to reduce the amount of water left over in the bilge. This reduces odor and helps keep the bilge cleaner. Hidden air vents within the body help prevent air locking in challenging plumbing installations and helps with the check valv