1íóintroduction The sympathetic vibraion acoustics uses the latest resonance principle design, a combination of precision parts, shell of casting zinc alloy material, and color by special oxidation treatment technology, to ensure that never fade, this product is no need exernal power supply, the only thing you have to do is connected to the computer and put it on plane to sound.Support by variety of desktop, notebook usb audio putput. 2íóparameters Operating voltage:5v Input mode:pc usb interface Rated impedance:4 ohm Frequency response:100hz-18khz Maximum power output:3w System support:windows 2000, windows xp, windows vista, windows 7 3íócomponent parts Sympathetic vibration acoustics usb cable Spare silicone manual Waranty card certificate packing box Size:150mm*100mm*63mm Weight:410g