https://www.zytrailerparts.com/products/underslung-suspension/ This is also called underslung suspension, with hanger thicknesses of 6mm, 8mm, and 10mm. It is used with Q235 steel, with heavy and light duty axle seats. The equalizer pin has 50mm,60mm and 70mm type with steel and copper bush. This has different models. Utility trailer suspension manufacturers have bulk trailer suspension parts for you to choose.