Like the CCM663SR, this is a dual, two-way ceiling speaker combining two offset tweeters and a twin voice coil bass/midrange driver to allow either for a combined stereo signal from one speaker, or for rear-channel surround sound. This speaker features a 150mm (6in) woven glass fibre cone bass/midrange driver and soft dome tweeters, as well as a two-position stereo/surround switch to instantly change between modes.