These SKB 3R Series Mil-Std cases were designed to meet the most demanding military specifications. They are roto-molded for strength and durability, airtight and waterproof with solid stainless steel latches and hinges that will withstand the most demanding shipping conditions. The 3R Mil-Std. Cases are molded of (LLDPE) polyethylene impact resistant / UV stabilized material and meet or exceed MIL-STD 810 and MIL-C-4150J specifications.