The TC-Series Hazy Aluminum Insert Timpani drum heads feature outstanding projection and sustain, with bright, focused sound and enhanced articulation. Featuring a 7.5-mil Hazy film combined with an Aluminum Insert ring for added tuning stability and projection, TC-Series Hazy Aluminum Insert Timpani drum heads provide the ideal combination of projection, sustain, and focused attack making them ideal for outdoor use, especially for Marching applications.