A compact and versatile doweling jig that allows woodworkers to create any dowel joint quickly and accurately. It has two retractable edge stops to quickly line up boards. The self clamping design allows for easy setup. The JointMaster™ comes with three drill blocks and is capable of creating joints using the most common dowel pin sizes- 1/4", 5/16” and 3/8”. Each hardened steel drill block is adjustable to accept and align centered dowel holes on boards from 1/2” up to 3”. Built-in scales help to align and center your dowels. The convenient centering marks make sure your holes are where you want them. If you’re using standard 1/2”, 5/8”, 3/4, or 1-1/2” boards, three included Spacer Blocks will automatically align the drill blocks and help you select the appropriate dowel size.