【Strong Signal for Long Range】 This waterproof wireless doorbell has 2 Transmitters 1 Receivers, The penetrating wireless signal can be transmitted up to 300m in an open space and at a long distance even with many obstacles (doors, walls). You will never miss any of your visitors. The doorbell does not interfere with other equipment at home or your neighbors. 【Waterproof and Intelligent LED Design】 The wireless transmitter made of superior material is waterproof to IP44 standard, stable performance is guaranteed for outdoor use. Blue LED on the button and receiver is a visual indication for host and visitor, it is also a fun and thoughtful design for the hearing impaired. Visitors know if they have used the right doorbell, because it lights up when used. 【36 Melodies and 4-Level Volume】 High-quality speaker, adopt the most stable music chip, built-in 36 melodies, Create clear and pure sound. Four adjustable volume levels from 25db to 85db. When the bell rings, you can easily hear it