Aquarian Super-2 drumheads sound louder fuller and more powerful than conventional 2-ply heads with the added over-ring control and focus of Studio-X Rings. They have great attack projection and depth unlike any other drumheads. The patented Safe-T-Loc hoop prevents the head from slipping and the Sound Curve collar design provides Responsive Tuning. With Responsive Tuning one turn of the drum key and Super-2 heads react. A free tuning sheet is enclosed with each Super-2 drumhead. Attack projection resonance and Responsive Tuning are what Super-2 s are all about.