The ERC Backpack holds a "Jumbo D" cylinder or Spiracle "DD"- Lite carbon fiver cylinder and provides hands-free operation with convenient backpack straps. Easy access to the Oxygen regulator is provided through a quick-acces flap. The ERC includes and extra strap to carry over-the-shoulder like a duffle bag, complete with reflective strips for night visibility and five custom hook-and-loop labels for each compartment. Available in Green.