Boying Portable Wireless Doorbell Kit Operating At 900ft/ 280m Range/ 1 Push Button (Transmitter) with 1 Plug-in Door Chime (Ac Receiver) & 1 Battery-powered Door Chime (Dc Receiver)(black) Simple and stylish appearancemade by new ABS material,no harm to the human body 36 tones, the user can freely chooseSuitable for more occasionsAdjustable volume Remote control distance of up to 280M/900Feet,Use radio frequency transmitter technology,have ten million group coding,effectively avoid outside interference Energy saving,Maximum power is only 2WStandby power consumption 0.5W Transmitter waterproof designdo not worry about rain or snow