self centering doweling jig Extended can be used to make accurate butt joints,miter joints and edge joints as well as acting as a mortising guide.Self Centering Dowel Jig PLUS can be used for more wider material, on boards of different thicknesses(clamping wide capacity: 3/8inch to 6inch). Easy to install and use. Suitable for drilling guide and wood board joints, it is an Perfect tool for panel furniture.Made from aircraft grade aluminum,more stable, corrosion resistance.Accurate positioning: fixture bolts provide very good threads, and provide bushes of different sizes to realize simple and convenient precise drilling,so that the positioning is more accurate, no offset or gaps are leftThe steel block and clamping screw handle securely tightens the tools like a vise, and the fine thread spacing of screw handle provides uniform and stable clamping pressure for clamping the workpiece. The jig with rugged aluminum sides holding work securely without damage to the wood.There are 4 drill guide holes, along the top of the jig,2 holes accept 7/16inch and 1/2inch drill bits directly.the other 2 holes accept threaded replaceable steel bushings.Material:Aluminum + Steelcolour:GoldPackage Contents:1 x self-centering pin holder2 x Steel 1/4inch Drill Bushings2 x Steel 5/16inch Drill Bushings2 x Steel 3/8inch Drill BushingsOnly the above package content, other products are not included.Note: Light 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.