CONTROLLED SOUND(TM) heads are single ply ambassador(TM)-weight heads with a 5 mil thick black or clear dot in the center of the head. This combination offers a controlled, centered sound without undesirable overtones. Dual Zone These dual-zone heads have a combination of medium and heavy-duty drumhead characteristics. The outer area of the head's playing surface offers a mid-range tone and sensitivity while the laminated center "dot" eliminates high frequency overtones and adds durability and tonal focus to meet the demands of heavier hitters. Ideal for snares CONTROLLED SOUND(TM) heads are ideal for snares!