NOTE: This cannula does not include a flowmeter. To purchase the A5 flowmeter, search for "A5 Solopack" SKU:2000047 The Oxymizer is a type of nasal cannula breathing device that has an oxygen-conserving reservoir in the face piece. The soft and lightweight Oxymizer conforms easily and comfortably to the user's face. NOTE: Oxygen equipment is non-returnable.