Features: [Wireless Design] Compact and portable in size and weight, convenient to install and remove. [Melody Selection] This Chime provides a choice of 52 different melodies. When it is plugged in, you can press the select button FORWARDS to play previous music and BACKWARDS to play next music until you hear a chime you like. [Sound Volume Selection] Press the VOLUME control repeatedly until the desired volume is achieved. 4 levels are available as a circle, lowest level is mute. [Pairing with Wi-Fi Video Doorbell] Press and hold VOLUME button for 4 seconds until the LED indicator lights up, and Wi-Fi video doorbell enters into pairing status. Then press the button on the doorbell within 5 seconds, pairing is completed once LED indicator on the Chime is rapidly blinking. When above procedure is finished, pairing will quit automatically. [Multiple Pairing Modes] Two or above Wi-Fi video doorbells choosing the same music; two or above Wi-Fi video doorbells pairing with different music; two or above chimes pairing with same Wi-Fi video doorbell. (The specific operation method is detailed in the Users Manual.) [Pairing Memory Clearance] Press and hold VOLUME button after plugging into household socket for 10 seconds to erase all pairing memory. When the LED indicator is blinking, it means that the setting is successful and the program will return to default.