Waterproof Wireless Doorbell 1 2 Button 1 2 3 Receiver 300M Remote Intelligent LED Light Home Door Bell Wireless Chime|Doorbells(black)Features and specifications1.The button supports up to 20PCS, and the receiver supports up to 100pcs.2.The transmitter without screw chuck design to achieve waterproof and dustproof.3.Eye-catching backlight flashes when someone pushes the doorbell. Particularly suitable for the elderly, deaf, and pregnant women.4.Uses machine-learning to prevent interference from other wireless transmitters.5.The transmitter USE a 23A12V alkaline battery (not include battery).6.Receiving distance:300 meters in open area7.The wireless signal will be affected by obstacles. The more obstacles, the more serious the signal loss.8.Receiver has 4 levels(can be mute) 0-80db,38 music to choose from.9.Size:Transmitter:77x46x20mm,Receiver:90x56x20mmNOTE:The button cannot be placed on an iron door because it will interfere with the signal.How to pair signalsPairing method: Press and hold the volume button on the receiver for about 4 seconds, then immediately press the button, the signal is successfully paired.