HD Cross Bed Boxes Constructed with heavy - duty .080 diamond plate aluminum reinforced by expert craftsman hand TIG welded seams, the HD Cross Bed boxes keep equipment safe and dry. Reinforced and insulated high dome lid features an ultra - tight weatherproof bulb seal, adjustable J - bolt striker mount, and heavy - duty aluminum piano - style hinge that bolts lid to box body for unequaled strength and durability - even in the coldest weather.