【Plug and Play】- The wireless doorbell is easy to install and use, all you need to do is plug the receiver into a standard power outlet and use the included double-sided 3M tape to install the transmitter outdoors. Complete the installation in 3 minutes! Easy to use, no need to pull cables, no need to drill into the wall! 【8 Levels Ultra-Adjustable Volume】- The wireless doorbell uses the most stable music chip in the industry. It can better penetrate walls to ensure a more reliable connection. There are 36 songs in the doorbell for you to choose from. You can use the music selection button to browse through these 36 songs, which can provide 8 volume levels. Press the music button once, the music gradually increases from level 1-8. 【Long Wireless Range】- The doorbell has a wireless frequency of 433 MHz and a very wide range, which does not interfere with other devices in the house. A sufficient radio speed allows bells to be installed anywhere in the house. It is also an ideal replacement for traditional bells, traditional bells have been Fallite and can alert elderly patients and nurses. 【Memory Loss Prevention Function】- The wireless bell has a memory function when powered off, which remembers the volume and music selected before power off, so there is no need to worry about losing information. In addition, the doorbell uses a low-power design that can save energy and be in standby for a long time. 【LED Indicator Alert Person】-When the wireless doorbell is connected to 220 AC, the wireless Wi-Fi doorbell will play the selected music and the LED will flash and enter the code matching mode. If someone presses the bell, the doorbell will ring to ensure you don't miss any visitors or packages.【pl】