This automatic bilge pump switch is ideal for high performance applications. It uses stainless steel sensors to detect water level and has no moving parts to fail under the duress of rough water boating. The Water Witch also uses a slight time delay so that the bilge pump is not constantly being turned on and off by sloshing bilge water. In addition, the switch keeps the pump energized for 20 seconds after water leaves the sensors to ensure that all water has left the bilge hose. For all bilge pumps drawin up to 20 amps. NOTE: ALL SALES ARE FINAL ON ELECTRIC PARTS - NO RETURNS, REFUNDS, OR EXCHANGES.