McKesson Portable Demand Valve Emergency Oxygen System. Includes Oxygen "E" Cylinder (empty), Wheeled Cylinder Cart. Demand Valve - 40psi - with adult face mask, tubing and attachments, regulator and gauges, and a chain attached cylinder wrench.There is also included an adult passive Face Mask, tubing and connector if only passive oxygen is desired. Please see the following for more information on a similar system with NO oxygen cylinder. The item "McKesson Portable Demand Valve Emergency Oxygen System" is in sale since Wednesday, May 8, 2019. This item is in the category "Business & Industrial\Healthcare, Lab & Dental\Medical, Lab & Dental Supplies\Other Medical, Lab & Dental Supplies". The seller is "melfuesting" and is located in Danville, Illinois. This item can be shipped to United States, Bahamas.