Omega Products Castleated Collet Nut for Collet Extensions (ER16) provides a secure, reliable connection between toolholders and collet extensions, delivering stability and precise results in milling, drilling, and other machining tasks. Built for professionals and hobbyists alike, it supports repeatable clamping and dependable performance in busy workshops. The castleated design enables fast, tool-assisted tightening and loosening with a standard wrench or spanner, helping you change tools quickly without compromising grip. Castleated tightening design: The castle-shaped notches allow secure tightening with a standard wrench, making quick tool changes faster without sacrificing grip. Secure hold on collet extensions: Engineered to hold collet extensions firmly in place for enhanced stability and precise machining under load. Durable, high-quality construction: Built from robust materials to resist wear and deliver reliable performance in demanding environments over time. With the Omega Castleated Collet Nut, you gain dependable, fast setup for collet extensions, reducing downtime and enhancing repeatable results across your projects. Its strong grip and durable build help maintain accuracy through repeated tool changes, making it a reliable addition to any lathe, milling machine, or CNC setup.