A long, permanently mounted pilot steadied by a floating sleeve lets you align holes that are spaced far apart. Tighten or loosen the two nuts on the reamer to move the adjustable blades within the diameter range so you can ream multiple hole sizes with the same tool. These reamers are often used for reaming bushings to a precise fit when the size needs to be determined during assembly. Blades can be reground and replaced. To measure size, adjust blades to a known size (such as a bushing or ring), or measure across two opposite blades with a micrometer.