Trolley case means a case with a trolley and rollers. It is widely used because of its convenient use, carrying clothes and so on. At the same time, the trolley case is also equipped with a pull rod, which can be divided into single tube pull rod and double tube pull rod, and the tube of pull rod can also be divided into square tube and round tube, so as to facilitate dragging when walking and greatly reduce the burden. The trolley box can be carried or dragged by hand. The wheels of the trolley box of that we usually use are basically at the bottom of the box, while the modern people have designed a new type of trolley box, which is designed as a cylinder shape, and the wheels are wrapped on the outside of the box. Such roller design makes the trolley box better adapt to the situation In the same terrain, you can easily go up and down the stairs by pulling the box directly. It is mainly made of cloth case, ABS hard case, leather case, PC and so on. Its usability is divided into three categories: directional wheel, universal wheel and the latest detachable universal wheel pull rod case