2.0 active USB speaker for laptop, PC, MP3, MP4,mellow and clear timbre, built-in acitve amplifier, Impedance: 4ohm, RMS: 3W+3W 2.0 active USB speaker for laptop, PC, MP3, MP4,mellow and clear timbre, built-in acitve amplifier, Impedance: 4ohm, RMS: 3W+3W mini speaker, pc speaker, USB speaker