OVERVIEW: A GREAT GIFT for homeowners, people who live alone, the hearing impaired, anywhere you need a safe guard Easy Installation - The door chime and door sensor are already paired. The first step is to stick the sensor on the door/window (the distance between the two parts should not exceed 0.4 inches), and the second step is to plug the chime receiver into the socket. Installation is completed! Upgraded Battery - Using household alkaline batteries, designed with ultra-low power design,...