Unique Bargains RC-36 NO Recessed Wired Security Window Door Contact Sensor Alarm Magnetic Reed Switch White

This Recessed Door Contact Sensor works with any access control or burglar alarm system available

NO means Normally Open: when the magnet separates, the circuit is conductive( light on ); When the magnet together, the circuit is not conductive ( light off ).

The Magnetic Door Switch must be installed according to the sensing distance; It can only provide a switch signal to the transmitter; It cannot directly load the power, nor directly connect the lamp!