Product Description Warm and round with a full sustain, the 10mil 1-ply EQ1 utilizes an internal removable EQ muffle ring, a fixed internal overtone control ring, and dry vents to provide a pre-EQ'd sound. The sound is controlled, but cavernous. It's ideal for ambient rock and can open up a drum that sounds too dry with other heads. From the Manufacturer Evans 18" clear EQ1 single-ply bass head contains an internal overtone control ring with a removable muffle ring and dry vents to provide a pre-EQ'd sound that is controlled, but cavernous.Evans EQ1 series features a single ply of 10mil film. A fixed internal overtone control ring can hold a removable EQ muffle ring for additional damping. Dry vents around the perimeter of the drum head offer a focused and articulate sound. For over 40 years, Evans has been a pioneer of drum head manufacturing and design. Known for innovative designs such as EMAD, EC2S, and the Hydraulic series, Evans drum heads are made in the USA in a state of the art manufacturing facility. Acquired in 1996 by D’Addario and Company, the global leader in musical instrument accessories, the Evans brand is synonymous with quality and consistency.