Ludwig Ultimate Marching Bass Drums are designed for modern marching groups, featuring 6-ply North American Maple shells, 10-ply hoops, and oversized tension claws. Maple brings high sensitivity, a wide tuning range, and a biting attack to your bass line. Each drum is constructed with 45-degree bearing edges with a 1/8" radius round over, finally hand-sanded to assure a completely flat surface to seat the head correctly. A bladder mold and a special adhesive help the shells cure evenly across the entire surface. This unique method makes the shells incredibly strong to hold up under immense tuning pressure.