Bad Dog Tools Arbor Set includes two sizes (¼” and ⅜”) to fit a multitude of discs, cut-off wheels, blades, and sharpening stones. Ensure your blade, wheel or disc stays secure on your power tool so you can use them all at the high speeds they require while keeping the tool stable. To use: simply insert the ¼” shank into the power tool, place the wheel over the top of the arbor, and screw in the appropriate sized arbor hole to the base. Use a flat head screwdriver to tighted the arbor and secure the wheel in place.