KEF CI160.2QS. Tweeter size: 19 mm, Woofer size: 130 mm. RMS rated power: 50 W, Frequency range: 50 - 40000 Hz, Impedance: 8 Ом. Type: In-wall/On-wall/In-ceiling speakers, Dimensions (WxDxH): 180 x 96 x 180 mm, Audio output channels: 1.0