Snugpak Rocket Pak System. OD Green durable, lightweight, waterproof nylon construction. Three rucksacks in one. Can be used fully zipped together providing 70 liters (4270 cubic inch) capacity. May also be used as a smaller 40 liter (2440 cubic inch) bag by unzipping the two detachable side pockets (rockets). The rockets can also be zippered together to provide a smaller 30 liter (1830 cubic inch) capacity bag. Zip on detachable side pockets are compatible with army issue yoke.