Evans EMAD2 series features two plies of film. The outer ply of 6.5mil and an inner ply of 10mil film provides an enhanced attack, focus and durability. The unparalleled industry standard Externally Mounted Adjustable Damping (EMAD) system allows the player to adjust attack and focus. 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 Remember, accessories ship fast and free from Sam Ash Direct BD20EMAD2 - 20" EMAD2 Clear