Our NEW Carbon Fiber Cylinders are manufactured by Worthington (formally doing business as SCI). They are built around DOT specifications and have a working pressure of 2216, 3000, or 4500 psig. These cylinders are lightweight, composite cylinders consisting of an aluminum alloy inner shell, with a total over wrap of carbon fiber, fiberglass and an epoxy resin. They are rated for 30, 45, or 60, minutes in duration. Your choice of color and make of valve assembly. SCI's cylinders are manufactured to the same specifications and standards as our leading new SCBA competitors.