C. Axle: Stud hub or spider axle,12 to 20 tons payload, can be same design as BPW D. Axle Tube: One piece type, axle if fabricated from one steel tube without welding E. Air suspension system, most parts imported from Germany. F. Landing gear: Single side operation or twin side operation landing gears for semi-trailers. Can be same design as JOST, HOLLAND, KIC