Total RMS output: 1.5 watts&.nbsp.Total peak power: 3 watts&.nbsp.Power supplied by USB port from desktop/notebook&.nbsp.Selected 50×50 mm speakers for clear sound&.nbsp.Glossy front panel&.nbsp.Volume control&.nbsp.Works great with any computer system using a standard 3.5mm audio plug&.nbsp.Compatible with Win7 Vista XP Mac 10.nbsp. Don`t be limited by a power adapter Genius releases cute mini speakers SP-U115 whose power is supplied through a USB port from a desktop/notebook. They use 50mm speaker drivers for loud and clear sound performance for a total of 1.5 watts RMS. It has a convenient knob on the side to adjust the volume. Just insert the USB plug to a PC/notebook for power and the 3.5mm audio plug into music playback device such as a PC notebook MP3 or CD player and enjoy music with the SP-U115. The cable length between the two speakers is approx 90cm. The USB cable and Jack cable length are both approx 110cm.