The overall body is made from aircraft grade aluminium alloy and the dimensional scales are laser-etched for and accurate positioning.Supports up to 2.4inch, suitable for most boards and round when combined with a power drill, the drill sleeve is made from materials for strength and accurate positioning.5 standard SAE drill sizes, namely 1/4inch, 3/8inch, 5/16inch, 7/16inch and 1/2inch; allows you to apply it to mortise and tenon joints, furniture and repair , making it the perfect tool for planking.color:GoldMaterial:Aluminum alloyPackage Contents:1 x self-centering Jig2 x 1/4inch hardened steel bushings2 x 5/16inch hardened steel bushings2 x 3/8inch hardened steel bushingsOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.