seamless steel cylinder Material: 34Mn2V, 37Mn,30CrMo standard:GB5099, JISB 8241, EN1964,DOT-3AA best quality&favorable price seamless steel cylinderMaterial: 34Mn2V, 37Mn,30CrMostandard:GB5099, JISB ... .8, 25EFilling gas: permanent gas and high pressure liquefied gas seamless steel cylinder