This sale is for 1 regulator, new with instructions. ThanksBonsai Pneumatic Oxygen regulator provides the highest savings ratio available on any pneumatic regulator. Delivers up to a 6:1 savings ratio. Liter flow increments: 1, 2, 3, 4, 5, 6 PLUS 2 CF presets @ 2 LPM. Operating pressure range: 200-3000 PSI. Senses a breath/delivers oxygen in the first half of the inspiratory cycle. Delivers a uniform oxygen pulse from 14-40 breaths per minute. Easy to operate single selector knob. Light weight, quiet operation, compact design. Fits easily in virtually any carry bag. This is the Bonsai Pneumatic Oxygen regulator.