Features:_x000D_ _x000D_ Made of premium material, high strength and hardness, strong structure, durable in use. _x000D_ High quality ER16 collet block for spindle motor shaft clamping. _x000D_ Spiral linear thread, more convenient clamping, faster replacement, high clamping force. _x000D_ Smooth surface, no scratches, stable performance. _x000D_ Suitable for lathes, drilling machines, milling machines, boring machines, can clamp tap, drill, milling cutter. _x000D_ _x000D_ Specification:_x000D_ Model: C20-ER16-40L_x000D_ Nut type: ER16A_x000D_ Body length: Approx. 40mm / 1.57_x000D_ Axle hole: Approx. 6mm / 0.24in_x000D_ _x000D_ Approx. 8mm / 0.31in_x000D_ Approx. 10mm/ 0.39in_x000D_ Approx. 12mm/ 0.47in_x000D_ _x000D_ Approx. 16mm/ 0.63in (Optional)_x000D_ _x000D_ Package List:_x000D_ 1 x Collet Chuck Holder