This pair of Morel ET338 Elite tweeters is acoustically matched from the manufacturer and based on the unique qualities of the famous Morel MDT 33. The new IDR™ (Improved Dispersion Recess) technology enables wider high frequency off-axis dispersion, resulting in a smoother overall performance. An aluminum faceplate with a newly refined texture offers extraordinary acoustical characteristics and exceptional quality finish. Also available in a 104 mm diameter faceplate . Replacement diaphragm .