☆We are a drum head manufacturer that produces highly uniform drum heads using innovative ideas and computer control.☆ The popular EMAD series bass drum heads, which boost low end and attack with a unique external removable damping ring, now include the EMAD Heavyweight, boasting the highest durability, volume, and sound pressure. This is the first bass drum head to feature LEVEL360 specifications, and like the tom and snare heads, it reduces tuning time and expands the tuning range, resulting in a more resonant, powerful sound than ever before. Available in five sizes, from 18 to 26. Thickness: 10mil + 10mil + EMAD with patch Size: 24 inches <LEVEL 360> The new structure allows the head to fit snugly against the bearing edge of the drum shell without stress, by finishing the entire 360-degree circumference of the head horizontally and making the corners more vertical, thereby widening the internal diameter. This is a proprietary EVANS technology that makes tuning easier, expands the high and low frequency range, and provides tone stability and improved sound quality.