... :GB5099, JISB 8241, EN1964,DOT-3AA best quality&favorable price seamless steel cylinderMaterial: 34Mn2V, 37Mn,30CrMostandard:GB5099, JISB 8241, EN1964,DOT-3AAWorking ... temperature: -20°C~60°C Neck thread: PZ27.8, 25EFilling gas: permanent gas and high pressure liquefied gas seamless steel cylinder