The Orbit is the perfect hybrid of double-ply and single-ply bass drumheads. Attack was able to capture the low frequencies and durability of a double-ply head while maintaining the beautiful open sound of a single-ply head. At Attack, we strategically removed portions of the under-ply, to open the head up and let it sing without sacrificing low frequencies: we call this vacuity. Technically speaking, the Orbit batter bass drumhead is comprised of a 10 mil clear Dynaflex film for the top-ply. For the under-ply, Attack uses a 10 mil nebulous white Dynaflex film with calculated sized and placed orbs. For our resonant ported bass drumhead, we replace the under-ply head with the 10 mil black Dynaflex film. Attacks chose to include the Holz branded 4" porthole to protect and give that perfectly finished appearance.