Respiratory - Oxygen Aids - CHAD Bonsai Velocity Pneumatic Oxygen Conserver : Delivers a uniform oxygen pulse at increments: 1, 2, 3, 4, 5 and 6. Two continuous flow (CF) settings preset @ 2 LPM and 4 LPM. Delivers up to a 6:1 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. Light weight and quiet operation. Easy-to-operate single selector knob. Compact design fits easily in virtually any oxygen carry bag.