Most of the collets used in the market are made of aluminum alloy. This material is soft and easy to wear and tear, so we use a better quality brass material. For plastic nuts, they will break during use, and the all-metal material solves this quality problem very well. Compatible with all for rotary tools and flex shaft. But except discontinued Models 1, 2, and Series 1 or earlier of discontinued Models 260, 270 and 280. This replacement brass collet provides a big improvement in precision and holds these tiny bits far more securely and in better alignment with the rotation of the tool, under high-speed rotation, it not only maintains stability but also improves work efficiency. The package contains: 8pcs brass 4485 collet (0.8mm, 1.2mm, 1.5mm, 1.8mm, 2.0mm, 2.4mm, 3.0mm, 3.2mm) and 2pcs metal change collet nuts. Colour:yellow Material:brass Package Contents: 1 set * for collet set Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.