Wireless Door Sensor Bitiwend Door Chime Doorbell with 600ft Operate Range 58 Chimes 5 Volume Level Led Indicator Door Open Alarm For Business

Easy Intallation: Pls install it AFTER pairing.Plug the receiver into socket tear off the tape behind door sensor then paste on the door. Specification of Door Sensor Alarm. Installation gap: 1cm. Pull out the strip on the door sensor part and plug the receiver into outlet.