Booster is a device that converts low pressure air power into higher pressure fluid or air power. When relatively small volumes of high-pressure fluid are called for intermittently, boosters show obvious advantages over continuously running hydraulic systems.Features: Power Factors of 1.9 to 4.8 . Bores 2-1/2” & 4” Outputs of 4.9 or 12.5 cu in per inch of Stroke Strokes to 6” in 1” Increments. Prelubed with Magnalube-G® Grease. Air Service to 150 PSI. Air to Air or Air to Oil Continuous Cycling Available. Front Face-Rear Face-Foot-Extended Tie Rod Mounts.Many Options.