1)O2 cylinder. 2)Material: 37Mn; 34CrMo4; 34Mn2V. 3)Certification:CE, DOT. Steel Oxygen Cylinders:Application Standard: GB5099; ISO9809; EN1964-1; JISB8241 Temperature Range: -40 ~ 65 oCFilling Medium: oxygen, high-purity oxygenMaterial: 37Mn; 34CrMo4; 34Mn2VCertification:CE, DOT