R&B Fabrications Pacific Coast Series bags and packs are the highest quality line available. The outer shell is constructed of 1000 denier Cordura® nylon. Designed to hold a "D" or Jumbo "D" oxygen cylinder with access to the regulator through the end pocket. The molded Tuff Bottom provides an almost indestructible base. Four outside pockets surround the main compartment. There are two pockets on the front that have multiple elastic loops and slot pockets. Inside the lid is a large zippered pocket. YKK #10 heavy duty nylon zippers are used throughout the bag. The zippers are reversed to eliminate wear on the coil prolonging the life of the strongest zipper on the market. It comes with an adjustable nylon shoulder strap.