Large boxes are difficult to transport with their contents. But depending on what you use the crates for, you may need to move them from time to time. So that you no longer have to carry heavy boxes, there is a practical rolling board on which you can place the boxes and then simply roll them from A to B. It's also great if you store boxes under cupboards or shelves and need to move them from time to time, as the rolling board makes moving them back and forth child's play.