iSeries 3913-12 Waterproof Utility Case (empty) SKB iSeries Injection Molded Mil-Standard Waterproof Cases are molded of ultra high-strength polypropylene copolymer resin, and feature a gasket sealed, water and dust tight submersible design (MIL-C-4150J / IP67) that is resistant to corrosion and impact damage. Other standard features include molded-in hinges, patented trigger release latch system, comfortable, snap-down rubber over-molded cushion grip handle, convenient strong push button release pull handle, automatic ambient pressure equalization valve (MIL-STD-648C), and resistance to UV, solvents, corrosion, fungus and impact damage (MIL-STD-810F).