This is an original large-diameter low-profile wheel cutting jig. Simply remove the back cover, set the wheel, replace the back cover, and cut with a craft saw. You can easily cut the tire mounting width to approximately 8.2mm. It is made of thick steel plate, so it is durable. Rust prevention has not been specifically applied, but a light rust-preventive oil will be applied before shipping. If the saw blade becomes dull, it will be difficult to cut from about the last 1/3. In that case, try flipping the wheel upside down and cutting. You can also insert something like Tamite to adjust the cutting position.