Birch Medium Density Wood Suited for Recording Studios and situations where contolled sound is needed. Greater High Frequencies, reduced Midrange and good low-end punch. Technical Specifications: Ply: 6x Birch Thickness: 5.4mm Diameter: 14 Bearing Edges: Standard 30° Exterior and 45° Interior Bearing Edges - Possibility to request the shell without bearing edges. Shell not drilled. The holes for the lugs, strainer, air vent and butt plate have to be drilled. You can use the Sparedrum drilling layout LO16 or LO26 to help you placing the future holes. Use Hard Wood Drill Bits to drill correctly the shells - Mesure and double check drilling holes diameters with the hardware you want to mount of your future drum. 5 years Guarantee Made In Italy Exclusive manufacturing processes developed by CVL in order to achieve the best sound and use less glue than other drum shell makers. The Manufacturing and the Drum Shells are certified ISO 9001. Eco-Sustainability is a big deal at CVL, the goal is to improve constantly to reach the smallest impact on the environment. You want a special shell, with your choice of woods, CVL can do it. Ask your favorite dealer for more info.