The rSeries Mil-Standard cases have been designed to meet the most exacting military specifications. They are roto-molded of impact-resistant/UV stabilized LLDPE for strength and durability, featuring airtight and waterproof construction with solid stainless steel latches and hinges that will withstand the most demanding shipping conditions.Our rSeries cases come standard with an empty interior. Proudly Made in the USA SKB iSeries Cases are molded from a proprietary blend of ultra high-strength polypropylene copolymer resin that makes them both lighter and 2.8x stronger than the competition. Every iSeries case is designed, manufactured, assembled, and finished at our factory in Orange, California-and has been since the beginning. It's this unsurpassed commitment to quality and innovation that makes SKB Cases the gold industry standard for military-grade protective cases.