Features 1、Made of premium material, high strength and hardness, strong structure, durable in use. 2、High quality ER16 collet block for spindle motor shaft clamping. 3、Spiral linear thread, more convenient clamping, faster replacement, high clamping force. 4、Smooth surface, no scratches, stable performance. 5、Suitable for lathes, drilling machines, milling machines, boring machines, can clamp tap, drill, milling cutter. Specification Features: Made of premium material, high strength and hardness, strong structure, durable in use. High quality ER16 collet block for spindle motor shaft clamping. Spiral linear thread, more convenient clamping, faster replacement, high clamping force. Smooth surface, no scratches, stable performance. Suitable for lathes, drilling machines, milling machines, boring machines, can clamp tap, drill, milling cutter. Specification: Model: C20-ER16A-40L Nut type: ER16A Body length: Approx. 40mm / 1.57 Axle hole: Approx. 6mm / 0.24in Approx. 8mm / 0.31in Approx. 10mm/ 0.39in Approx. 12mm/ 0.47in Approx. 16mm/ 0.63in (Optional) Package List: 1 x Collet Chuck Holder Package List