Delivers a uniform oxygen pulse at increments: 1, 2, 3, 4, 5 plus CF present at 2 LPM. Continuously monitors breathing patterns and adjusts oxygen dose to match activity level. Achieves maximum conservation efficiency by automatically adjusting the dose down when less oxygen is needed. Delivers a quiet, gentle dose of oxygen using an efficient and compact design. Allows delivered dose to increase up to 2 settings during patient exertion up to a maximum pulse dose setting of 7. Can use 2 AA Alkaline or 2 AA rechargeable batteries for a duration of about 1 year for most patients. Operating pressure range: 500 - 3000 PSI. Weighs just 15.5 ounces with batteries. Auto shut-off feature conserves battery life. Fits easily in virtually any carry bag.