KoolAir Pumps PM500, Submersible, 500 GPH Marine Air Conditioning Seawater Circulation Pump Koolair pm500-115 magnetic drive pump is most commonly used for marine air conditioning & fountains Replaces lc-3cp-md march pump, includes fully integrated, heavy duty marine base and original base Maximum internal pressure is 25 psi and the maximum liquid temperature is 130 degrees fahrenheit The pump is dry run protected to withstand thermal overloads without failure The pump is epoxy encapsulated, which allows the pm pump to run fully submerged in many liquids