Artsound MD50. Woofer size: 101.6 mm. RMS rated power: 10 W, Peak Music Power Output (PMPO): 20 W, Frequency range: 50 - 20000 Hz. Weight: 0.92 kg. Type: In-wall/On-wall/In-ceiling speakers, Dimensions (WxDxH): 135 x 50 x 135 mm, Audio output channels: 1.0