Active Ceiling Speaker 5" with rear box. Power rating 15 W , 8 ohms impedance and a frequency response from 90-10000 Hz. Buil-in amplifier of 10 + 10 W (stereo) or 20 W (mono) with an output impedance of 2 ohms, powering up to 3 passive speakers for the right channel and 2 speakers for the left channel. Dimensions 132 mm (diameter) and 56 mm (depth). Without grille, to be used in combination with K875 units.