These single ply, resonant bass drumheads feature Aquarian’s patented "Floating Muffling System." They are perfect companions for the Super-Kick™ and Impact™ series batter heads and eliminate the need for external muffling of the resonant head. The result is a bass drum that will tune up and mic up in seconds. The Regulator™ heads are available in Video Gloss Black or White.with choice of a large 7" ported hole in the center, a 4 ¾" offset port or a full head with no porthole.