Aluminum - heavy duty construction. Two separate storage areas keep forms and supplies organized. Lower compartment has 1" capacity and features a built-in pen tray. Upper compartment provides an additional 7/16" of storage capacity. Divider tray between compartments can be removed to create one large compartment. Self-locking latch keeps lid tightly closed protecting contents from elements. Stain resistant lacquer finish. Non-skid cork backing strips.