Delivers a uniform oxygen pulse at increments: 1, 2, 3, 4, 5, 6, 7 Plus CF preset at 2 LPM. Minimum 2-year battery life utilizing 2 AA batteries. Delivers a 5:1 savings ratio from 14-40 breaths per minute. Senses a breath/delivers oxygen in the first half of the inspiratory cycle. Operating pressure range: 200-3000 PSI. Weighs only 14.9 ounces with batteries. Single push button selects the equivalent LPM dosage settings. Auto shut-off feature conserves battery life. Fits easily in virtually any carry bag.