Biamp Desono CMT20DTS - Two-Way 4.25-Inch Ceiling Loudspeaker (White)Priced individually, but sold in pairs. The versatile Desono CM20DTS 4. 25" two way design built in ceiling loudspeaker produces a dynamic and warm sound ideal for high quality background music and voice reproduction. The back can with only 83. 5mm (3. 287") built in depth is probably the shallowest in his kind. The uncompromised sound quality and controlled sound performance makes it suitable for any kind of ceiling structure. The CM20DTS has a