The Quantum Mark II Snare Drum features a six ply shell for a warm overall sound and a special snare bed that provides superior snare response. The Quantum Mark II Classic Snare Drum features a six ply birch-maple blended shell for a warm overall sound, a unique snare bed that provides superior snare response, and a rugged full size design for maximum projection.The reduced shell depth of the Agility model offers reduced weight for outdoor applications and a more focused sound for indoor applications.