The Dremel 69-Piece Cut-Off Wheel Assortment includes 69 assorted cutting pieces that allow you to cut metal, wood and plastic and to cut or slot bolts, screws, sheet metal, thin wood and plastic. for use with all Dremel tools. for best results, insert the accessory bit all the way into the tool and then back it out slightly before tightening down. This provides plenty of shank for the collet or chuck to hold onto the bit.