[Out of the Box] This door chime has been paired before delivery. No need for wiring or electrician installation: simply plug the receiver into the socket, and glue the door sensor to the door with the provided double-sided adhesive, and you're ready to go. [Longer Range] Up to 1000 Feet in the OPEN AIR from the sensor (300 ft if there are walls). Cover your house or store, ensures you will never miss a visitor. Include one 23A 12V battery in equipment and design of Ultra-Low-Power, the battery can easily last 1-3 years. [Multiple Features] The door sensor chime is equipped with 60 different chime options and 5-level of volume range from 0dB to 110dB, so you can create a comfortable environment for your family. Silent mode with just LED flash is available when you don't want to be disturbed. [Sensor upgrade] In order to avoid battery consumption during storage and transportation, we added a power button on the sensor, if not used for a long time, please turn off the sensor to extend the battery life. [Distinguish Front and Rear Doors] All receivers will ring no matter which door is opened, but each door has a different tone, so you know where your guests are. If you want the sensor and receiver to work one-to-one, please try the steps in How to clear the frequency and re-pair . Brand Full House Color Black Voltage 12 Volts Item Weight 0.38 Kilograms Manufacturer 1 PLUS ONE Power Source Battery Powered Audible Noise 110 Decibels Maximum Range 1000 Feet Mounting Type Door Mount Control Method App, Touch Sensor Technology Contact Sensor Battery Description 12V Number of Batteries 5 12V batteries required. (included)