MP120B mixer amplifier has a wide range of output power ratings and enhanced cost-effectiveness with this model: 120W. The mixer amplifier is integrated with a USB player for MP3 playback. It is design to work with high impedance (100V) speaker system. The 5-segments LED output meter is to monitor the output signal level. It is standard 19” rack-mountable with earpieces provided and only takes up to 2U of space. This product can be called usb speaker amplifier, or a music mixer amplifier.