Wireless DoorBell Waterproof Battery Operated Loud Chime Doorbell Wireless Electronic Waterproof Houseware DC Mini Doorbell Doorbells blackFeatures:With good penetration and long receiving distance up to 300m open spaceEasy to install and no wiring requiredEasily mount on wall with double-sided sicker or screwsBuilt-in 55 ring tones optional and 5 volume level adjustable from 0 to 110dBThe transmitter is IP55 waterproofPerfect for office building, hotel, home, hospital, and moreSpecification:Receiving Distance: up to 300M open spaceVolume: 0-110dB, 5 level adjustableRing Tone: 55 ring tonesFrequency: 433.92MHz?R280KHzPower Supply:- Transmitter: 1* 12V 23A Battery NOT INCLUDED- Receiver: 3pcs AAA battery NOT INCLUDEDTransmitter Size: 35x85x15mmReceiver Size: 82x82x31mmNOTE:1. Dont mount this transmitter on a metal door, which will weaken the signal distance.2. The receiver should be as far away as possible from electrical appliances with large electromagnetic radiation.3. The actual signal receiving distance will be affected by use environment TV, computer, stereo, etc..Package Includes:1 x Transmitter1 x Wireless Receiver