USB powered multimedia speakers. Very good sound, bought for use on one of our laptops, though they work equally well on my Android phone. Remember, though, that it needs USB power to operate, so a wall-wart is required if connected to a device without USB power output. There is a built-in inline volume control, much easier to adjust than adjusting on the output device itself. We like them very much. Great bass response for small speakers, due to the porting of the speaker enclosures.