Safe And Durable Chuck:Crafted from alloy material, one-piece construction design and built-in spring make our 3-jaw chuck more secure and durable than plastic models. It can hold tiny drill bits more securely at high speeds, and the quick-change keyless drill chuck can hold a variety of mini drill bits ranging from 1/32” to 1/8”, eliminating the need for frequent rotary tool changes 7mm Collet Nut: Made of alloy steel, these nuts are wear-resistant, more durable, and safer than plastic alternatives. Coupled with brass collets, they offer exceptional adaptability and improved accuracy for precision work Brass Collets: Constructed from high-quality brass, these nuts are robust, resilient, and resistant to bending. The unique 4-claws design ensures powerful gripping, firmly holding drill bits in place. A range of clamping diameters adds to their versatility, making them suitable for a wide array of applications Multiple Sizes Available: The set includes a variety of sizes of brass drill chucks, from 1/8" to 1/50" (0.5mm to 3.2mm) to meet the different needs of users and reduce the hassle of purchasing additional accessories Highly Compatible: Compatible with all Dremel cordless and corded rotary tools (including drills, sanding drums, buffing wheels and other lightweight attachments). Compatible with Dremel rotary tools: 200, 285, 300, 3000, 395, 398, 400, 4000, 4200, 4250, 4300, 8000, 8100, 8200, 8220, 8260 Multifunctional: This drill chuck collet set is compatible with most Dremel rotary tools available on the market. Whether it's a drill, polishing wheel or cutting wheel etc, it's easy to handle. Suitable for electric grinders, drills, extension flexible shafts, engraving machines and other polishing and sanding tools Cost-Effective: We considered that when the M7 and M8 are sold in combination, some may feel wasted because they don't need one of the collets. And now we separate them so that one can buy only just the collet they need instead of paying the price of the whole combination. Buying on demand reduces the cost of purchase Comprehensive Packaging: Your purchase includes 15pcs of drill chuck collet accessories: 1 replacement keyless chucks, 1 metal collet nuts, 10 brass 4485 collets, 1 super-thin open-end wrench, and 1 L-wrench. Please note: Tips: Please check the size before buying. Contact Information: Your account → Your order → Seller: mizhiaheng → Ask a question. If you have any questions, please feel free to contact us. Safe And Durable Chuck: M7x0.75mm universal multi chuck, one-piece construction design and built-in spring make our 3-jaw chuck more secure and durable than plastic models. It can hold tiny drill bits more securely at high speeds, and the quick-change keyless drill chuck can hold a variety of mini drill bits ranging from 1/32"" to 1/8"" in size.