Visaton SL 87 WPM. Driver size: 83.8 mm (3.3 "), Mid-range driver size: 80 mm. RMS rated power: 20 W, Peak Music Power Output (PMPO): 30 W, Frequency range: 200 – 5000 Hz. Weight: 0.24 kg. Type: In-wall/On-wall/In-ceiling speakers, Dimensions (WxDxH): 83 x 83 x 29 mm, Audio output channels: 1.0