Visaton FR 9.15. Driver size: 101.6 mm (4 "). RMS rated power: 15 W, Peak Music Power Output (PMPO): 30 W, Frequency range: 75 – 16000 Hz. Diameter: 150 mm, Weight: 0.277 kg. Type: In-wall/On-wall/In-ceiling speakers, Dimensions (WxDxH): 155 x 95 x 34 mm, Audio output channels: 1.0