The magnetic door lock is you can unlock it when the power is off. This magnetic lock can be used for single doors. This magnetic lock is suitable for wood / metal / glass / stainless steel, and fire extinguishing doors. This shell is made of high-strength aluminum alloy. It has DC12V or DC24V input voltage, 500 x 47 x 26mm lock size, 180 x 38 x 11mm dimension, 4Kg weight.