This is a power powered Bluetooth - WiFi speaker. Part of Yamaha MusicCast - multi room system (similar to Sonos). Can be used individually, controlled by ph application or paired with another speaker(-s) like this for stereo or multi room music system. More information about speakers It here:

https://usa.yamaha.com/products/audio_visual/desktop_audio/wx-030/index.html.

Features :

Exceptional sound clarity and rich bass from a compact powered speaker that looks great anywhere in your home
Works with your home Wi-Fi network as a standalone music system or expand over time with other MusicCast speakers, sound bars and AV receivers to add audio in up to 9 additional rooms
MusicCast app lets you access all of your music from your mobile devices, Pandora, Spotify, Sirius XM Internet Radio, Napster and thousands of free internet radio stations
Also supports Bluetooth and AirPlay so you can play almost any content; Bluetooth streams can be redistributed to other MusicCast devices via Wi-Fi

What's Included :

Yamaha MusicCast WX-030 Speaker
Power supply cord

Condition :

This is used, in good condition, fully functional speaker. There are few surface marks on the body from regular use and handling. Tested fully and sounds great. See images for details.