The MW X C ArkivA(R) Side Roll compartment is made from the same Ultra and EPX fabrics as our NASA pack and works perfectly for adding more capacity and organization to the core design. The side rolls are fully weatherproof and ideal for transporting Cylindrical items such as water bottles and camera lenses.The MW X C Mars Project Arkiv accessories come equipped with four custom orange Arkiv Clips and a Fidlock closure buckle for quick and secure access. As with all Arkiv accessories, the side roll can easily be removed from the pack and used as an external organizer.Each NASA Arkiv pack is equipped to hold two side accessories and one front accessory. Made in the USAExternal Dimensions : 10.5" x 5" x 3"Internal Volume : 10.5" x 4" x 2.75"Weight : 0.5 lbs