Complete 4-Piece Set: Includes 2× 1/2-Inch (12.7mm) Router Collets and 2× 1/4-Inch (6.35mm) Router Collets, offering a comprehensive solution for both standard and precision routing tasks Precision Fit & Superior Grip: Crafted to deliver a tight, vibration-resistant hold on your router bits, these collets ensure stable operation even under heavy loads. The precise 12.7mm and 6.35mm dimensions minimize runout. Wide Compatibility: Fits For Dewalt 326286-04, DW621, DW616, DW618 series;Fits For 1617, 1618, 1613, MRC23EVSK, MRF23EVS series ;Fits For Hitachi 323-293; ;Fits For Craftsman routers. Whether you're upgrading worn parts or building a backup kit, this set fits seamlessly across multiple major brands. Durable Construction: Manufactured from hardened steel with a wear-resistant finish to withstand the torque of high-speed routing. These collets resist deformation over time, maintaining a secure grip session after session—ideal for professional shops and frequent-use job sites where reliability matters. Convenient 2+2 Configuration: Each size comes as a 2-pack, giving you a spare for each common collet type. No more downtime searching for a replacement mid-project; keep one in your tool bag, ensuring you're always ready for the next cut, groove, or decorative edge. Quick Identification & Easy Installation: The two distinct sizes allow for effortless selection—use the 1/2″ (12.7mm) collet for heavy-duty bits requiring maximum stability, and the 1/4″ (6.35mm) collet for finer detail work. Each piece is designed for straightforward installation with standard router wrenches, getting you back to work in minutes.