Differentially set ringtones: Different buttons set different ringtones, easily distinguish between front and rear doors. Built-in 38 music/3-level volume adjustable. This doorbell does not need wiring, plug and play, convenient and practical, easy to installThe receiver is suitable for direct plug-in, the applicable voltage range is 100-240V 50/60Hz. Applicable scenarios: residential, hotel, , hospital. Function: Learning CodeRemote control distance: Indoor distance is about 50 (without partition),Outdoor open space is about 100-300 . (This data is the experimental test distance. The actual distance is affected by the applicable environment and obstacles. The more obstacles, the shorter the distance. The actual distance is subject to the experimental environment distance)How to use: Packaged are paired they leave the , and no need to pair again.Pairing : The receiver socket is plugged into a regular household socket. When the power is on, (if different transmitters need to correspond to different ringtones, first press the music button to select the ringtone) and then press the receiver mode button for about 5 seconds until the indicator light flashes. Enter the pairing mode, at this time, press the transmitter, the receiver rings, the pairing is successful.Clear the code: Press and hold the receiver pairing button for about 10-13 seconds until the indicator light quickly. After blinking, stop blinking, is, clear all pairing codes.Receiver parameters1. Working Voltage: AC 100-250V 60Hz/50Hz2. Power consumption: 0.5W3. Operating Frequency: 433.92 MHz4. Operating temperature: -10C~+45C5. Volume: 25~85dB (3-level volume adjustable)6. Receiver Size: L95xW54xH68mmTransmitter button parameters1. Working Voltage: 12V2. Battery Type: 23A 12V3. Transmitter Size: L80xW45xH21mmDoorbell Type:WirelessType:DoorbellsItem Name:Plug Type:US Plug,it applies to Canada, ,Mexico, Thailand, the , the Philippines,Taiwan and so on.Voltage:AC100-240Vcolor:WhiteMaterial:plasticPackage Contents:1 x Receiver1 x DoorbellOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.