Equipped with preset vacuum switch, which prevents operation of heater if pump is not running * Union adapters included to connect with any 2-Inch pump suction line; 115V * Includes high-limit switch to guard against overheating * For use with whirlpools only * Heater can be field installed on: Amiga, Bianca, Capella, Cetra w/ skirt, Cetra 536, Fresco, Gallery 5 Oval, Gallery 6 Oval