The compact HomeFill II revolutionizes ambulatory oxygen by allowing patients to fill their own cylinders from their Invacare® 5-liter concentrator. With HomeFill II, providers virtually eliminate cylinder deliveries, reducing costs by three-to-one, and patients enjoy their freedom and independence with an unlimited supply of ambulatory oxygen. The HomeFill II Oxygen Filling System allows the patient to breath at home from a continuous flow concentrator and then use a convenient ambulatory pack when they are “out and about”. The Patient Convenience Pack available for the HomeFill uses the latest in integrated pneumatic conserving technology for a 3.7-to-1 ratio while remaining lightweight. This new cylinder combines all the patient independence and provider cost savings realized with the Home Fill II delivery model plus carefree convenience and simplicity. The convenience pack (available in ML6 and ML9 sizes) requires no batteries, no cumbersome connection tubes, and uses a standard single lumen cannula. It allows the patient to quickly fill an ambulatory cylinder and go where they want, when they want.