Logitech V20 USB Powered Notebook Speakers (Grey) S-0155A High dynamic headroom circuitry offers greater volume with less distortion Lightweight, portable design Plug & Play Connection - USB provides power and digital quality audio, no other cables are necessary Total RMS Power - 2 Watts into 4 ohms at 1 kHz at 10% total harmonic distortion (THD) Combined with the 2 inch Max-X high-excursion drivers and 3 inch pressure drivers, maximize bass response