3pcs RC33 NO Recessed Wire Door Contact Sensor Alarm Magnetic Reed Switch White Capillary Thermostat * This kind of wheeled

* This kind of wheeled carriers are fit for "I" beam curtain track

space light

): 21mm / 0

07-inch x 0

you can mount one more brackets to separate the weight

3pcs RC33 NO Recessed Wire Door Contact Sensor Alarm Magnetic Reed Switch White Capillary Thermostat * This kind of wheeledDescription: 1. NO means Normally Open: when the magnet separate, the circuit is conductive( light on ); When the magnet together, the circuit is not conductive ( light off ). When make order,pls check carefully! 2. These are the door contact sensors that are in use with any and all commercial or residential card access systems as well as all security burglar alarm system. 3. Work as an anti theft alarm, perfect for metal door and window.