4 different diameters to choose from: diameter: 13.75-15.25mm ;Excellent Quality: Adjustable manual reamer, made of high-speed alloy steel, high hardness for rust protection, durability and long service life. Main function: suitable for casting process boring and craft processing; cannot be used on the machine, which may damage the blade, only by hand. Wide application: widely used for bore machining, installed in drilling machine, milling machine, etc. Package content: 1 adjustable hand reamer. Features: The blades are adjustable and move in the tapered slots in the reamer body. To adjust these reamers, the blades are moved in these slots by loosening the nut at one end and tightening the nut at the other. The movement allows the reamer to be set to any desired diameter within the size adjustment range. The adjustment feature allows the reamer to maintain a specific size by compensating for wear. Can be readjusted to expand and regroup to proper size and sharpen. Can only be used by hand, use on a machine may damage the blade.