600 D Nylon. This concealed-carry pack is the SPARTAN 1 Sling Bag. The SPARTAN 1 is equipped with an ambidextrous strap which allows for quick access. The three storage compartments are large enough to tote a trauma kit, binoculars, ammunition, or many survival essentials. A concealed-carry sleeve on the back panel of the bag easily and comfortably houses a pistol. Lazer cut Molle on the front of the bag for quick attachments. THIS BAG OFFERS A GUN HOLSTER/ VELCRO BACKING, FOR EVERY DAY CARRY (EDC).