i-Auto Time Wireless Doorbell (Operating Range - 300M/1,000FT | 52 Chime Tunes | 4 Volume Levels | LED Indicators) - 1 Remote Button, 1 Plugin Receiver-white 12V 23A ALK battery for the push button remote is INCLUDED. Wireless doorbell operating at Maximum of 1000ft / 300m in open air. 52 different chimes. 4 levels of adjustable ringing volume from 25~110 dB No batteries required for the receiver. Simply plug it into a power supply (120V US Standard) Built-in LED indicators create visual alert Screws and double-sided adhesive tapes included for easy installation of the transmitter