Convoluted foam in lid, 1" solid foam floor and 2" custom cut foam glued on top of floor foam. Watertight, crush-proof and dust proof construction. Double Throw latch system. Automatic Pressure Equalization Valve. O-ring seal. Fold down handles. Polyurethane wheels with stainless steel bearings. Stainless Steel hardware and padlock protectors. Two (2) Padlock Eyelets. Unconditional Lifetime Guarantee.