Widely Used: The wireless doorbell has 55 kinds of ringtones and 5 volumes to adjust ("mute" at level 4). Suitable for home, apartment, classroom, office. It can also be used as a paging device for the elderly, pregnant women, patients, etc., to attract attention when you need it most. LED Flash: The flashing blue LED on the button and receiver is a visual indication for the host and visitor, it is also a fun and meticulous design for the hearing impaired, as it lights up when in use. The distance between the receiver and the transmitter can be up to 300 meters. Wireless Waterproof Doorbell: With wireless connection technology (connected by radio) and IP55 waterproof level, allows you to choose the position of the transmitter and receiver wherever you need it, it can withstand bad weather. Outdoor Dress for Home, Garden, Office, School, House, etc. Durable Low Consumption: This IP55 waterproof doorbell works between -30°C and 70°C (-22°CF and 158°F), withstands various harsh weather