Evans Hydraulic coated drumheads feature two plies of thin film offering maximum durability, and a fat, deep and short sound pioneered by early 70's rock and roll. Unique translucent coating delivers additional warmth, focus, and depth. Hydraulics are famously easy to tune, making them a perfect fix for troublesome drums and players with little tuning experience. Both Red and Blue are 2 plies of 7mil film while Black is 6.5 mil over 7.5 mil. For over 60 years, Evans has been an innovator in drumhead manufacturing and design. As the creator of the first synthetic drumhead and other revolutionary products such as EMAD, Hydraulics, and the UV1 series, Evans drumheads are designed with the intent of solving problems for drummers. Regarded for high quality and consistency all Evans drumheads are made in the USA and feature Level 360 Technology.