This Portable Wireless Doorbell has a high-quality sound that comes with 6 tunes and has a range of 250 ft. (76m). You can conenct up to 4 transmitters simultaneously, such as push buttons and awareness devices (door contacts, motion sensors). It is an easy installation with a portable or wall mount option, with a wall mounting kit included. The weather resistant, surface mount, Push Button has an illuminated Halo LED feedback and Wireless "E" Push-button compatibility. 1) Battery Life of the doorbell is up to 2 years, 2) Honeywell ActivLink robust signal, 3) Doorbell requires 4 AA alkaline batteries (not included), 4) The CR2032 battery for the Push Button is included, 5) LED Strobe Alerts. White.