diameter: 10mm length: 100mmExtension 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 efficiencySpring Collect is highly clamping force, wide clamping range, high accuracyWidely used in boring, milling, drilling, tapping, grinding and other processingColor: silver + blackMaterial: Steel chuck model:C10 ER8A 100LSpring Collect Gripping Range:2MM to 5MM(2mm,25mm,3mm,35mm,4mm,45mm,5mm)Spring Collect MODEL:ER8Package include:1 x Straight chuck7 x Spring collectOnly the above package content, other products 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.