Our CNG cylinders have passed the evaluation of ISO11439 certification ... industry. Our product list for export as followings: 1) Type II CNG CYLINDER FOR VEHICLE (ISO11439, BV approved)OD325mm: 40L ... 80L,145LOD406mm: 80L 90L, 100L.,120,145L2) Type I CNG CYLINDER FOR VEHICLE(ISO11439, BV approved) OD232mm:20,25 ... Thank you very much! Best regard Lisa liu CNG Steel Lined Glass Fiber Hoop Wrapped Cylinders