Bass Head Evans Externally M Damping Clear 22 BD22EMAD Original With an offset 4” microphone port in a single ply of 10mil film plus a foam dampening ring around its edge, the EVANS EMAD Resonant series gives you greater control of your overtones, so you can enhance your pitch, focus, and attack. Treatment: Uncoated Ply: 1 Thickness: 10mil Technology: EMADMade using a single ply 10mil film The perfect resonant head for use with the EMAD series batter heads A fixed, internally mounted black plastic control ring holds in place a foam damping ring that controls overtones The 4 #34; offset mic port features a plastic sleeve that focuses pitch and enhances the attack while providing protection for the port All EVANS drumheads are designed, engineered, and manufactured in the USA