Pioneer S-IW551L CST Series In-Wall Center Channel Speaker (Discontinued by Manufacturer) Coherent Source Transducer (CST) Technology, Left Center Right 1.5-Inch-Inch Aluminum Tweeter and 5.25-Inch-Inch Mica-filled IMPP Woofer 120 Watt Power Handling For home theater or multiroom applications that demand performance Superior to pivoting driver designs, Pioneer CST speakers offer an affordable Speaker Dimensions:20.67"(L) x 3.35"(W) x 8.86"(D).