DURAGADGET Small USB Tablet Speakers For Samsung Galaxy Tab 4 - 7.0 / 8.0 / 10.1 & Samsung Galaxy Tab 3 - 7.0 / 8.0 / 10.1 Active portable speakers, ideal for tablets Power supply via USB port (bus-powered) with a 3.5mm Jack Plug Volume control dial Frequency range: 320 Hz - 20 kHz Sine-wave power output: 2x 180 mW (total harmonic distortion &lt;3%)