Segawoot Wireless Door Chime Operating at Over 900 Feet with 2 Plug-in Receivers,CD Quality Sound 52 Ring Tones to Choose,Black Operating range of 200~700 feet through the metal security doors and wall. Remote transmitter is rated IP44 Waterproof and acceptable for outdoor use. 52 Different Ring tones. 4 levels of adjustable volume from 30dB to 110dB. Plug receiver into a standard outlet in room (AC 110V US). CE, FCC, Rosh certified. Push button powered by 12V 23A battery, working temperature from -30 to 70. Push button designed with a message box. Visitors can leave a note to you or You can leave a message to your visitors.