TOMPACK: EC2 CLR SST - RCK Evans EC2 series features two plies of 7mil film with optimized attack, tone, length of sustain and ease of tuning for each size head. The Sound Shaping Technology (SST) Edge Control ring mounted on the underside delivers an extremely well balanced and pre-EQ'd sound across the full kit by varying the size of the ring for each different head size.Rock Tom Pack (10"12"16") drum heads are made using two plies of 7mil film. Two plies offer consistency and durability for longer playing time. Exclusive Sound Shaping Technology (SST) provides the ideal amount of dampening tailored for each individually sized drum head. Also available in a coated version with a unique translucent appearance. All Evans drum heads are designed engineered and manufactured in the USA.