The outer shell is constructed of Cordura® nylon. Four interior options make these bags extremely customizable. Choose from a fully padded insert with adjustable dividers, a padded insert with oxygen tank straps and pouch pockets, a “Z” Pak removable storage insert, or keep the main compartment empty. All insert options may be removed for cleaning. The bag is designed to hold a “D” or Jumbo “D” oxygen cylinder, with access to the regulator through the end pocket. The 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. #10YKK heavy duty nylon zippers are used throughout the bag and are reversed to eliminate wear on the coil, therefore prolonging the life of the strongest zipper on the market. It comes with an adjustable nylon shoulder strap. Available color choices are: red, orange, and royal blue. It weighs 130 oz. and has overall dimensions of 27”L x 15”W x 12”H.