Make of brass, which is not easy to rust and is enduring. The foot valves inner wall polishing , smooth surfaces, none scaling, none clogging, practical and enduring. The bottom valves is generally used for auto priming pumps (water pumps) to filter debris to entering the pumps. The brass bottom valves only needs to be threaded to the suction hose, none complicated steps are required. Perfect for deeply well pumps, centrifugal pumps, irrigation systems, household water supply, industrial pipelines, and building water supply and drainage systems.