Lock when energized, unlock when power fails. Super tension, built-in surge absorbing circuit. Fine workmanship design, no mechanical wear and long service life. Made of aluminium alloy, sturdy and safety in use. Professional electromagnetic lock, stable and reliable performance, warranty period of two years. Suitable for wooden doors, glass doors, metal doors, fire doors. Specifications: Material: aluminum alloy Lock pull: 60kg linear pull Input voltage: DC24V Working current: 3A-5A Package Weight: 539g/19.0oz Package List: 1 x Lock 1 x Iron Block 1 x Bag of Screw 1 x User Manual Note: Insufficient suction, one is whether the input voltage is enough to 24V, the other is whether the installation is correct, mainly to see whether the iron plate is installed very hard, the installation requires the iron plate to be able to shake left and right, and cannot be fixed, otherwise it will not work well with the magnet If you touch it, if you don't touch it, the suction will be insufficient. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.