Remote Controlled doorbell is an innovative product which has an hassle-free installation without the need of any changes in electric wiring. It can be installed very easily without having an technical knowledge. That the battery included is only for the switch. Use 2 AA batteries for the main unit. Carefully remove the back cover of the switch and install the provided battery It comes with 32 different musics. Light touch button two side tape included, Can also be wall mounted Range: 100 m in open and 50 m with obstacles Clear sound This is for home, school, office, hotels, factories Flash light turns on while guest presses the remote button.