Product Information: EVANS EQ3 Resonant No Port drumhead series is a popular choice for both players and engineers. This drumhead features a single ply of 10mil film with a 10mil internal overtone control ring, delivering a warm and punchy sound with a controlled, short decay. Product Features: 28" resonant drum head made using a single ply of 10mil film A fixed, internal overtone control ring is made to be microphone friendly, from the studio to arena No mic port For more information and specifications, please refer to the manufacturers website