Features:The doorbell adopts wireless high-frequency emission technology, effectively avoiding the troubles caused by mutual interference between neighbors and false alarms.Plug-in receiver plugs into any standard outlet and any suitable scene.Easy to mount and requires no wiring, simple and fast installation.In addition to being used as a doorbell, it can also be used for special purposes such as contact, paging, patient care and emergency notification.The wireless doorbell can be installed at will, and the button can be installed or pasted. It is suitable for home, office, hotel, building, dormitory, factory, construction site or any space that needs service.Specification:Material: ABSColor: Main WhiteTransmitter Power: <10mWReceiver Rated Voltage: AC 100-240VReceiver Plug Type: US plugReceiver Volume Range: 25-75dBReceiver Standby Current: <1.0mATransmitter Size: 8.1*4.9*2.1cm / 3.2*1.9*0.8inReceiver Size: 8.1*4.9*2.1cm / 3.2*1.9*0.8inNumber of built-in MP3 ringtones: 16 (external extended ringtones are not supported)Package Weight: Approx. 154g/5.4ozPackage list:1 x Self-powered Transmitter1 x Wireless Plug-in Receiver1 x User manualNote:Due to the difference between monitors and light effects, the pictures may not reflect the actual color of the item.Please allow slight measuring error due to manual measurement. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering..