60 Melodies with 5-Level Adjustable Volume: The wireless doorbell offers a wide selection of 58 chimes for your personal taste. 4-level of volume works from 20 dB to 110 dB. | High Performance Transmitter: Ultra-low power consumption; uses a 23a12v alkaline battery that boasts 2 year maximum lifespan; IP44 dustproof and waterproof; working temperature ranges from -4 °F-140 °F, withstands various harsh weather conditions. | Long Range Up to 1000 Feet (300 m) in Open Space: Ensure that you never miss any important guests or urgent deliveries even if you are several rooms away. This wireless doorbell works perfectly in kitchen, bedroom, living room and so on. | Easy Installation: Just plug the receiver into a wall outlet, install the push button with provided double sided tape or screw it on the wall (screws are included). | DIY Expandability and Low Power Concumption: You can expand each transmitters with up to 10 receiver. Code learning function makes it easy to customize your doorbell with multiple transmitters and receivers. Powered by 23A 12V battery, the transmitter is tested to ensure up to 10,000 times of press for daily use, eliminating needs of replacing battery frequently.