Edifier USA 2.0 USB Computer Speakers (R19U) Active USB bookshelf speaker Angled design to optimize listening experience 23/4 inch (70mm) full range drivers with dual magnetic circuit design Master volume with built-in power switch USB audio streaming capability and AUX input Wooden enclosure to minimize acoustic resonance USB: 650 mFS50 mFS AUX: 500 mV50 mV