The wireless digital door chime sound is melodious and tuneful. The appearance is compact and uniquly. The remote control range is 100 meters. By installing it is simple and easy, you can lay it anywhere. The all-weather anti-interference system is designed, 1/100000 of the numbers encrypt the code, remove the neighbour and external world from interfering completely, there is no vexation sounded definitely. We design it at Saving electricity module, input voltage is 220V.Model: ETF0004