With eight different diameter chipping holes ranging from 8mm to 20mm and fixed screw holes for each diameter, this tool is incredibly easy to use. Simply rotate the red tool holder to your desired diameter gear, tighten the screws, and you're ready to create circular wooden strips of various sizes. It's a must-have for mortise and tenon structure enthusiasts, engineers, carpenters, and decoration workers. If you know someone who's passionate about DIY, this tool makes for an excellent gift. The package includes the adjustable electric drill milling round rod tool, a carbide blade, a T20 blade wrench, a 5mm adjustment wrench, and 3 setscrews. Overall, it's high-quality and incredibly versatile.