Nylon, polyurethane PU, TPR, PP, rubber and other materials are different, although they belong to the medium-sized caster series, but the load-bearing range is still different.
尼龙、聚氨酯PU、TPR、PP、橡胶等材质，因材质不同，虽同属于中型脚轮系列，但承重范围还是有所差异的。
