Bench Dog Tools 50-37801 Beadlock Pro Kit Beadlock system overlaps drill bit holes precisely to accept a special Beadlock loose tenon Index lines on the guide block allow you to precisely align the jig with your reference marks. Handles stock thicknesses of 3/4-Inch and up. Includes all necessary hardware for cutting 3/8-Inch joints. What's in the Box? Beadlock Pro Jig 3/8-Inch HSS Drill Bit 3/8-Inch Stop Collar 3/8-Inch Beadlock Guide Block 3/8-Inch Mortise Paring Guide Block For more information on Beadlock Pro, see this blog post from Popular Woodworking Magazine.