1) 2 pieces multimedia speaker system2) Two-channel audio class-D Amplify for speaker driving3) No AC adapter or sound card required4) Supports USB suspend function5) USB powered, 64-level volume control6) Total output (RMS) 1W + 1W7) Frequency response 20 - 20kHz8) Impedance 4 ohmsInner packing: Unit Size: 159*75*46mmGift Box(paper)Outer packing: 100pcs/ctn producing area:China payment:T/T in advance or 30% deposit and 70% T/T before delivery supplying capacity:3000pcs/day