NOTE: This cannula does not include a flowmeter. It is only compatible with the X3 On-Demand Conserver. To purchase the X3 On-Demand Conserver, search for "X3 On-Demand Solopack" SKU:2000003 The X3 Demand Boom Cannula is designed to provide easy access to oxygen without sacrificing comfort and performance. With a simple mount to your headset, the X3 Demand Boom Cannula uses a dual lumen cannula and features a swivel arm and fully adjustable arm to give you the best fit. The X3 Demand Boom Cannula is convenient, comfortable, lightweight, and works with your existing headset. The X3 Demand Boom Cannula is configured for a left side mount to the headset. NOTE: Oxygen equipment is non-returnable.