Evans EQ4 Frosted Bass Drum Head, 22 Inch 22" drum head with fixed internal overtone control ring proportional to the size of the head An internal overtone control ring and a removable muffle ring coupled with dry-vents work extremely well with and without a microphone Single ply of 10mil film offers full, wide-open tone Also available in a clear version All Evans drum heads are designed, engineered and manufactured in the USA