Mapex Quantum Bass DrumIntroducing the Mapex Quantum bass drum Quantum Mark II Bass Drums features a maple shell and a consistent 14 shell depth throughout the lineup. The new externally eyebolt system allows for easy eyebolt height adjustment to suit each individual player without removing drumheads. The six ply maple shell with SONIClear bearing edges provides a warm and full resonant tone with enhanced reinforcing rings for strength and durability. Each drum model is