Physen&reg; Europe style Model FXB2t1 Wireless Doorbell Kit of 2 Transmitter & 1 Receiver Package including: 2 push button(transmitter),1 door chime( receiver), 23A 12V Alkaline battery, screws& double-sided adhesive tapes. High quality ABS frosted material. Inspiration designed comes from music symbol. Very arty. It looks like jumping notes when pressing the push button. Over 50+ different ring tones. Operating range of 1000 feet in open area. Four levels of adjustable volume from 25db to 110db. Receiver: easy plug-in design(Please DO NOT plug receiver into UPS units); Transmitter: Powered by 23A 12V Alkaline battery. Easy installation: plug receiver into standard socket, fix transmitter with double-side tape or screws For Model Music Symbol, a perfect use case scenario for this product would be if you have a front door and a back door , you can program each button to a different tone so you can know which door someone is at