The balance precision of the product is higher than that of the common nut.Extend the service life of the nut, improve the durability, better ensure the use of the machine, and enhance the anti-wear and anti-friction.Buy now. Features: 1. Suitable for ER type tool handle, tool bar, extension bar nut holding drill bit, boring cutter and other tools. 2. Strong clamping force is not easy to deform. Hardened and precision ground.Black Oxide Finish. 3. This collet nut is a great replacement for the broken part, fit most tool holders. 4. Very wear-resistant, high corrosion resistance, so very durable. 5. Suitable for ER25 chuck, tool handle and tool rod. Specification: Condition: 100%brand new Material: 42crMo Weight:130g Color: black/white Size: 4.5*4.5*2.5cm/1.77*1.77*0.98inchapprox 1mm=0.039inch(approx) Color: nut thread : nut diameter(mm) nut height (mm) black m32*1.5 42 21 black m32*1.5 42 lengthen white m32*1.5 42 21 Package list: 1*Collet Clamping Notice: Please Check Pictures and Specifications for Compatibility. Due to the light and screen difference, the item's color may be slightly different from the pictures.