Wireless Home Electronic Doorbell Features and specifications 1.The button supports up to 6 PCS, and the receiver supports up to 100pcs. 2. The transmitter has no screw chuck design, and it can be waterproof and dustproof without rubber ring. 3.The transmitter USE a 23A12V alkaline battery (not included battery). 4. Receiver voltage: 110-220V. 5.The receiver is available in a variety of plugs, US/EU/UK Plug and AU adapters, suitable for most countries. 6.Receiving distance:300 meters in open area. 7.The wireless signal will be affected by obstacles. The more obstacles, the more serious the signal loss. 8.Receiver has 4 levels 20-80db,36 music to choose from. 11.Size:Transmitter 77x46x20mm,Receiver 90x56x20mm. NOTE:The button cannot be placed on an iron door because it will interfere with the signal. How to pair signals? Pairing method: Press and hold the music button on the receiver for about 5 seconds, while pressing the button, the signal is successfully paired after ringing again. How to modify and lock music? Press and hold the volume button of the receiver before plugging in the power socket. Plug in the power socket until the light of the receiver lights up, release the volume button, press the music button to adjust to the favorite music ringtone, press and hold the volume button again until When the light is on, press the transmitter twice immediately and the music is locked successfully. How to solve if the work is not normal,When receiving the goods? 1. Try pairing signals first 2. Please contact us, we will send a video to help you 3. If there is a problem with the product, we will re-send the receiver or button to you.