ER11 Collets: new Material: steel Color: silver+black Total height: approx. 18mm Outer diameter (max): approx. 11.5mm Gripping range: 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm Built in self-Release design and tools will never get stuck in holder. Use with any standard ER collet chucks for coolant-thru tool applications. Each collet is well packed in separate protective container with label. Hardened and precision ground. Performance stability, high accuracy. Durable in use. Widely used, boring, milling, drilling, silk attack, sculpture, CNC, and other processing. ER11A 5mm Extension Rod: new Height: approx. 40mm (when the lock nut) Shaft Hole: 5mm (-0.02 mm) the need to install heating expansion ER11A Nut: Outside hexagonal nut 19 mm maximum overall diamete High strength and hardness. Package included: 1 x ER11A 5mm Extension Rod 7 x 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.