Flambeau's HD Tuff Box features heavy-duty polycarbonate construction with an O-ring seal and rubber-bumper system so you can store essentials and know they're protected from moisture, bumps and falls. Zerust fights corrosion for added peace of mind. Clear lid lets you examine contents without opening. Pressure-relief valve for air travel. Heavy-duty polycarbonate construction O-ring seal and rubber-bumper system Clear lid lets you examine contents without opening Pressure-relief valve for air travel