The Evans EMAD2 Bass Drum Head, 22" is a double ply bass drum head with interchangeable dampening rings. This Externally Mounted Adjustable Damping (EMAD), allows you to tailor your drum sound between degrees of attack, sustain and low end. An external plastic sleeve holds either the narrow or wide foam ring in place. Without the ring, the EMAD2 produces an open and resonant sound with some control. Inserting the narrow ring changes the sound and enhances attack and focuses low end, but leaves ample amounts of resonance. The easy change to the wide ring maximises attack and low end while controlling sustain and delivers punch.