The Venture HomeFill II complete home oxygen system will revolutionize ambulatory oxygen by allowing patients to fill their own high-pressure cylinders from a concentrator. The Venture HomeFill is a multi-stage pump that simply and safely compresses oxygen from a specially equipped Invacare 5-liter concentrator into oxygen cylinders in sizes M6, ML6 and M9. The ability to fill their own cylinders gives ambulatory patients greater independence and freedom. Home care oxygen providers will also benefit from the virtual elimination of time-consuming and costly service calls associated with cylinder and/or liquid oxygen deliveries.