1509-AQN5 The Edwards 1 electromagnetic door holders feature housings finished with durable baked polyester powder paint. The floor or wall section houses the electromagnet while the contact plate attaches to the door. The contact plate has a shock absorbing nylon (swivel) ball that allows the plate to adjust to any door angle. Floor units are available in single-door or double- door (back to back) versions. Wall units are available in flush or surface mounted versions. If power fails, doors are released automatically but may be opened or closed manually at any time. All units are free of moving parts, are self-contained and require no maintenance. The device holders hold a door open while energized. When de-energized by a relay controlled by the fire alarm system or other switch, the door is released to a closed position.