Aquarian PF28B Performance II 2–Ply Clear – Size – 28"The Performance II is a 2 ply head manufactured with Aquarian's vacuum tuned process which eliminates air bubbles and wrinkles between the two plies. The two 7 mil plies are only sealed at the edges which tame unwanted overtones and puts a focus the low frequencies. The PFII is designed for loose tuning to deliver that low, fat, punchy tom tom sound that were a big part of classic rock and roll records. Frequency control that adds focused power is