[Long Distance Signal] The wireless signal with strong penetrating power can transmit signals up to 300m in open space and long distance even in the presence of many obstacles (doors, walls). [36 melodies and 4 volume levels] By pressing the button on the receiver, you can select 36 kinds of CD ringtones, including 4 kinds of adjustable volume levels from 25dB to 85dB. [Waterproof doorbell] The button of the transmitter is made of premium materials, and the waterproof level reaches IP44 standard, which can ensure stable performance when used outdoors without worrying of all weather conditions. [LED Flash] The button and blue LED flash on the receiver provide visual instructions to visitors and visitors. It is also an interesting and detailed design for the hearing impaired and will light up when in use. [Easy Installation] 2 steps to connect the portable receiver to any mains, and use the attached patch or screw to stick the transmitter on the wall. The receiver does not require batteries. Unplug the receiver so the ringer stops ringing. Product Name: Wireless door] Bell Color: White Sheet: European StandardSpecifications: (1 Transmitter + 2 Receiver) Waterproof: Transmitter Waterproof Degree IP44 Working Temperature: -30C to +70C Operating frequency: 433.92MHz + 75KHz Receiver Voltage: 100-260V / 50-60Hz (wide voltage) Transmitter Battery: 12V23A mercury-free environment protection battery (with certification) Product certification: FCC, CE, ROSH, appearance patent, etc. Ringtone: 36 optional, learning code, DIY Volume: 0-100 decibels, 4 levels adjustable Packing list: 2x receiver, 1x transmitter, 1x double-sided tape, 1x screw (without battery)