This listing is for a set of Large Dovetail jaws, which are used on the Hurricane HTC125 4 Jaw Woodturning Scroll Chuck. They can be used in compression mode for gripping a tenon or expansion mode for internal holding within a dovetail recess. These jaws are only compatible with the HTC125. Don"t have an HTC125? If you haven"t heard of the Hurricane HTC125 5" Woodturning Chuck, please check it out in our ebay store. It is a super high quality chuck, without the super high price of competitive chucks. Many jaw sets are available and inserts are interchangeable for use on today"s most popular lathes.