Feature: 1. [Adjustable Size Range] The lathe chuck features internal jaws that can be tightened in sizes from 2 to 2.5in (45 to 63mm), and external jaw that can be expanded inside the workpiece in sizes from 2.4 to 3.1in (60 to 78mm). 2. [Chuck Set] Includes 4 sets of jaws and gear, which are interchangeable, comes with wrench, thread adapter and tool box, providing great convenience. 3. [Premium Alloy Steel] Crafted from alloy steel, this lathe chuck is sturdy and built to last, with its well thought out design, ensures reliability and a long lifespan. 4. [Thread Adapter] The lathe chuck set features an adapter that allows for a change from 1in x 8TPI to M33 x 3.5TPI, providing compatibility. 5. [Wide Application] Suitable for general lathes, grinders, milling machines, drill presses, and other machine accessories, as well as woodworking machinery attachments. Specification: Item Type: Lathe Chuck Material: Alloy Steel Chuck Diameter: 3.75in Chuck Thread: 1in x 8 TPI. Package List: 1 x Lathe Chuck16 x Lathe Chuck (4 Set)1 x Wood Screw16 x Bolt Accessories1 x Chuck Wrench1 x L Wrench1 x T Wrench1 x Thread Adapter1 x Storage Box