Breathing Air Cylinder, 4,500 psi Pressure, Steel Cylinder Material. UN/ISO/DOT 4500 PSI/310 BAR, 444 CF, 152 Lbs – 67 Kg empty, 2750 CI – 45 Liters water .... Home · Products & Services · Specialty Cylinders · Aviation Cylinders; 49 CF ... Cylinder Weight (lb), OD (in), L (in), tmin (in), DOT Service Pressure (psi) .... Color, Yellow. Cylinder Material, Steel. Model Compatibility, Breathing Air Only. Pressure, 4500 psi. Size, 9.4" x 50.8". Style, With Valve. Tank