Z2 RF Plug-in ChimePlug-in Chime for Smart DoorbellColorPlug TypeSelectTech Specs Working Voltage AC90-250V Working Frequency 433.92MHz ± 280KHz Power Consumption 10mW Transmit 0dbm Sensitivity -110dbm N.W. 92g Volume Up to 100db Dingdong size 8.2*8.2*2cm In the Box 1 x Plug-in Chime 1 x Instruction Manual Safety Instructions Please install your doorbell according to this manual to avoid any malfunctions or damage; The Plug-in Chime is designed for indoor use only; The Plug-in Chime is not user serviceable, there is a danger of electric shock if opened; Use only high quality alkaline battery. Using poor quality batteries will reduce the maximum range; Do not expose either unit directly to rain/dripping or immerse in water; Do not mount either unit close to a fireplace or expose to high temperature; Never use any cleaning chemicals or wet cloth to clean the unit. Only use a dry, clean and soft cloth/micro fiber cloth; Do not position the Push Button onto any metal surface or UPVC door frames, as this will reduce the operation range; If not using the Plug-in Chime for long periods, unplug it from the socket and remove the battery from Push Button to prevent leakage; Dispose the old battery in accordance with the relevant legislation.