Patented Quad-Frame™ Foam Filled Lid Structure forms a solid insulated core for added strength, rigidity and solid, secure lid closure Over-sized push-button locks for easier one-hand access and key lock protection ToughCoat™ tub and lid liner reduces cargo damage, eliminates aluminum dust and increases box durability One-Piece, Heavy-Duty 0.080" aluminum base helps prevent sagging, leakage and minimizes denting