The TC-Series Clear Low-Profile Steel Insert Timpani drumheads feature bright, focused tonality with outstanding projection and sustain. Featuring a 7.5-mil Clear film combined with a Low-Profile Steel Insert ring for added tuning stability, sustain and projection, TC-Series Clear Low-Profile Steel Insert Timpani drumheads provide the greatest amount of sustain and projection of all Timpani drumheads, making them ideal for outdoor use, especially Marching applications. Available in extended collar sizes 22", 25", 28", 31" and 34". Other sizes 20" - 35" available by special order.