Electronic lock with boltThere are 2 elements, the fixed part painted black and the metal hook. You have to slam the door to close it and put 12v on the wires to unlock. The electromagnetic lock is mainly carbon steel material, the lock hook can bear 150kg pull. Precautions when plugging inThe lock should not be powered for more than 3 seconds and the voltage should be 12V 2A. If you use a relay with a digital code and when you unlock, everything turns off. Because the power supply is not powerful enough, you have to power the coil separately or put a dedicated power supply on the lock. Open via intercomThe lock can be opened via intercom with a little DIY. You just need to send a 12v and 2 amp pulse, so provide a small relay in the event of a lack of power with a 12v 3 amp power supply. Perfect for securing cupboards, so that children cannot access. Energy saving and long lifespanShockproof, anti-puncture and anti-theft protection. Mechanical life, when designing the load condition, about 500,000 times. Suitable for door from 0.5 to 4 kg. Easy to useElectro-magnet magnetic lock for easy installation, without limits on left, right, front, rear and position allows mechanical tab unlocking. Built-in unlock status detection. Size approx. 5.7 x 7.2 x 1.3 cm. Application for delivery cabinets, refrigerated cabinet, mailbox or newspapers, self-service cabinet, counter. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-dadangjia