PHODS M2 (The Portable Helicopter Oxygen Delivery System) is a man-mounted oxygen delivery system that can be attached directly to a crew member’s Survival Vest and helmet. PHODS has been specifically designed to supply rotocraft aircrews with supplementary oxygen when completing missions at altitudes above 8,000ft / 2,400m. Available with a suplimentry 'Mission Kit' this further expands the use and duration of PHODS by providing additional Oxygen Cylinders, allowing the user to quickly and efficiencly change from a used cylinder to a full cylinder, allowing further in mission time.