ER11 1-7mm Collet Chuck Total height: . 18mm Outer diameter(Max): . 11.5mm Gripping range: 1MM to 7MM (1mm,2mm,3mm,4mm,5mm,6mm,7mm) Fits metric size(s): For example,1mm Collets Fits 1mm metric ,2mm Collets Fits 2mm metric . ER11A 5mm Extension Rod Height: 38 mm(when the lock nut) Shaft Hole: 5 mm (+0.02 mm) the need to install heating expansion ER11A Nut: Outside hexagonal nut 19 mm maximum overall diamete Hardened and precision ground Built in self-Release design and tools will never get stuck in holder Widely used, boring, milling, drilling, silk attack, sculpture, CNC, and other processing. Use with any standard ER collet chucks for coolant-thru tool applications. Each collet is well packed in separate protective container with label. Colour: Silver Material: Carbon steel Note: The color of package is random, don't accept the specified color. Package Contents: 1 * Extension Rod 7 * ER11 Collets Only 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.