A cylinder or tube, typically made from bent laminated wood or occasionally from metal or synthetics. The type of wood used has a great impact on the tone the drum produces. Drumheads are mounted on one end or both open ends, along with various other hardware, to finish the drum. Shells come in a variety of diameters and depths; diameter affects the lowest note the drum can play, the depth affects the resonance and tone of the drum, as well as its volume and projection. The thickness of the shell affects the tone and the projection — a thinner shell will vibrate more and have a “woodier” tone (often preferred for recording), while a thicker shell results in a brighter, more intense and focused tone.