No battery is needed to generate electricity and transmit signals by pressing the transmitter, saving money and eliminating the trouble of replacing batteries.Waterproof grade IPX4 can be daily waterproof (not immersed in water) If installed in a completely exposed outdoor, please use a waterproof cover.The remote control distance is 150M (in an open environment), and it is normally installed in an indoor environment at 20-30M (depending on the thickness of the wall).38 Polyphonic ringtones can be selected with 4 levels of volume adjustment (high, medium, and low mute).Comes with adhesive and easy to install. The transmitter can be fixed and installed with screws (the accessories do not include screws).CharacteristicVoltage ac110 ~ 240V 50 / 60Hz.Working environment: - 10 ~ 45 .150M remote receiving distance (in open environment).4 Kinds of volume adjustment, mute can be set.Without batteries, mechanical energy generates electricity.Plug Type: EU Plug, it applies to Indonesia, Germany, France, Spain, Italy and so on.Colour: picture colorMaterial: ABSPackage Contents:1 * Receiver1 * TransmitterOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.