Long Range and Stronger Signal: Works within 300 meters in open space, this doorbell's signal penetrates obstacles very well. You can connect the receiver anywhere you want in your house. Nowireless interference problem. Super Easy Installation: The receiver requires no assembly or batteries, just plug in with an electrical outlet. The transmitter can be fixed to the front door with the supplied screws or stuck to the door with the included adhesive. Excellent quality and waterproof : This doorbell is made of ABS material, which is non-toxic and harmless. The transmitter is waterproof and acceptable for outdoor use. Protects against dust, rain and high temperatures.No electromagnetic radiation. Energy saving and long service life: low power consumption, energy saving and durable in use. LED Indicator: The doorbell (transmitter) and receivers have LED indicators, if someone presses the doorbell, all three devices will flash with blue light. 58 ringtones available Features: Wide application Satisfies all kinds of home decoration, official buildings, hotels, factories, commercial activities. Emergency contact for the elderly, pregnant women, patients, etc. Energy saving. Low power consumption, energy saving and environmental protection, the maximum power is 2W, standby power consumption is 0.5W. How to install the doorbell: You can fix the doorbell (transmitter) on the wall or door frame with the attached adhesive tapes or you can open the transmitter with the screwdriver in the box and fix it on a surface with the screws . Plug the receivers into any standard outlet you like and you can use the doorbell.