Excellent Material Our magnetic door lock housing is made of high quality ABS plastic with a matte finish for a high-end look. Strong Protection Our electromagnetic safety lock generates magnetic force by connecting the circuit. When the magnet is close to the switch, the Reed contact closes and the signal line is connected. If the door is open, the magnet leaves the switch, the Reed contact opens and the signal line is interrupted. Forced Opening Alarm Our alarm door lock will immediately send a signal to the host when someone illegally opens the roller shutter door 2-3cm. The host speaker will trigger a loud alarm to prevent illegal users from starting it. Widely Applicable Our security alarm door locks are suitable for shops, specialty shops, garages, supermarkets and other places. EASY TO INSTALL Our magnetic locks for doors and windows can be installed very simply and easily by following the steps of the instruction manual, without requiring too many tools.