Features Premium Material: The collet chuck holder is made of premium material, high strength and hardness, strong structure, durable in use. High Quality: High quality ER16 collet block for spindle motor shaft clamping. Reliable Performance: Spiral linear thread, the collet chuck holder can more convenient clamping, faster replacement, high clamping force. Smooth Surface: Smooth surface, the collet chuck holder no scratches, stable performance. Scope of Application: The collet chuck holder is suitable for lathes, drilling machines, milling machines, boring machines, can clamp tap, drill, milling cutter. Specification: Model: C20-ER16-40L 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