This electromagnetic lock is composed of an armature plate used for electromagnetic and access control door locks. Attach this to the door frame and attach the armature plate to the door, the current flowing electromagnetic attracts the armature plate and keeps the access control door lock closed. When power is off, the door will open. Suitable for wood doors, glass doors, metal doors, fire retardants etc. Function: Secure NC Mode: Unlocked when power off and locked when power on. Suitable for: wood doors, glass doors, metal doors, fireproof doors Anti-magnetic design, made of wear-resistant material High quality electromagnetic material vacuum processing, double locking body insulation treatment. Aluminum housing is made of high strength alloy and anodized Environmental protection requirements, low power consumption, ultra-quiet design, comply with no noise during operation. Various unlock function options: directly match building intercoms, such as keys, manuals, remote control, intelligent induction, telecontrol, etc. Specifications: Lock Mode: NC Operating Voltage: DC 12V Working Current: 12V / 400mA Material: Aluminum Alloy Shell + Iron Plate Holding Force: 180kg / 350Lbs Lock Size: Approx. 18.5 * 3.3 * 2.3cm / 7.3 * 1.3 * 0.9in Plate Size: Approx. 13.1 * 3.4a>