1/ This drill chuck collet chuck set fits for light-duty accessories including drill bits, sanding drums, polishing wheels, wire, bristle brushes and cut-off wheels. 2/ Compatible with Dremel rotary tools: 200, 285, 300, 3000, 395, 398, 400, 4000, 4200, 4250, 4300, 8000, 8100, 8200, 8220, 8260. 3/ Package Included: 1 x Quick Change Keyless Chucks, 2 x Metal Nut, 10 x Brass Collet, 1 x super-thin open end wrench and a Allen Wrench. 4/ The keyless chuck can hold various accessories from 1/32" to 1/8" shank sizes. The metal nut and the Brass Collet make a great improvement in precision and holds fine bits more firmly. It remains stable at high rotational speeds and increases working efficiency. 5/ If you have any questions during use, please contact us immediately. We will solve the problem for you at first time. Please measure the sizes before purchasing.