The 0018e circulator is a variable speed, high-efficiency wet rotor circulator with an ECM permanent magnet motor. Bluetooth capability. Dual electrical knockouts with 6 inch stranded wire leads for easy wiring. Operating modes include infinitely variable fixed speed to fine tune any zone, constant pressure for zone valve applications, proportional pressure for panel radiators with thermostatic radiator valves or self-adjusting activeADAPT auto mode. The 0018e is not suitable for chilled water or open loop potable water systems.