Rain Design Iwoofer for iPod Nano (White) Power Rating - Total 12 Watts RMS Satellite speakers - 2 x 3 Watts (4 ohm) 30mm full range drivers with neodymium aluminum speaker cones Subwoofer - 1 x 6 Watts (4 ohm), 2.5inch dedicated low frequency driver Power Supply - External AC Adapter (100-240V)