The Evans EC2 Clear Drumhead with SST is a two-ply head with 7mil each, with Sound Shaping Technology mounted underneath. By controlling edge vibration (instead of eliminating it), the ring isolates and damps higher overtones, enhancing low-end and attack, and enabling a broader tuning range with the EC2 Clear Drumhead with SST. Expect great durability, punch, and resonance with this Clear version of the Evans EC2 with SST.