This tool has been designed and manufactured for the precise alignment of frame and fork disc brake mountings. It mills every IS mount, Post Mount, and the new Shimano Flat Mount (Front Mount and Rear Mount). Includes two pairs of disc brake mount milling cutters: one pair for IS mount and one for Post Mount and Flat Mount. The cutters rotate simultaneously for fast and accurate milling operations. Both mountings are milled at the same time, ensuring both are processed parallel and evenly in one operation. The new generation of cutters allows for the processing of steel, aluminum, magnesium, and carbon surfaces. Please use cutting oil.