Shank diameter: 10mm Shank length: 100mm Extension rod diameter and the other parts are precision ground to eliminate unbalance, increase safety when cutting. It can reduce the use of extension tools, which can reduce costs and improve efficiency Spring Collect is highly clamping force, wide clamping range, high accuracy Widely used in boring, milling, drilling, tapping, grinding and other processing Color: silver + black Material: Steel Shank chuck model:C10 ER8A 100L Spring Collect Gripping Range:2MM to 5MM (2mm,2.5mm,3mm,3.5mm,4mm,4.5mm,5mm) Spring Collect MODEL:ER8 Package include: 1 x Straight shank chuck 7 x Spring collect Only the above package content, other are not included. Note: Light 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.