Features: 1) The pipes are 28mm to 168mm in outside diameter and 2mm to 16mm in wall thickness 2) The grade is 20G, 15CrMoG, 12Cr1MovG (GB 5310-1995), Gr. C (ASME SA-210), and Gr. T22 (ASME SA-213) Origin:China Payment:T/T, L/C Trade Mark:Double-Ring Packing:In bundle