Hydraulics International, Inc. (HII) portable Electric-Driven Gas booster is rated to 10,000 psi for breathing air/N2 and 4500 psi for oxygen service. Ideal for filling or topping off cylinders, tires, accumulators, struts and life rafts. Its two-stage and double-acting design uses no belts or pulleys, making it the quietest electrically operated booster in its class at only 60 decibels. Complete with safety controls, filters, gauges and valves.