Wireless Door/Windows Sensor
The wireless contact sensor is an accessory of smart alarm system.
It's fashion design, energy saving, and low battery warning supported. The system would inform users to replace the battery by App when needed. lt's easy to setup and works well with most doors and windows. When transmitter and magnet are apart, the sensor triggers alarm.
Transmitter can be put on either of magnet's left or right side.
Larmtek Wireless Door&Window&Cabinet Contact Sensor, DIY Home&Business Security Door Magnetism Sensor, On line check,Anti-Thief, CS01, White