Features: brand new and high quality HIGH QUALITY: Made of high quality 45# steel material and it will provide long-term strength and use for many years. PERFECT DEEP PROCESSING: ER straight chuck with extended handle, long handle, suitable for deep hole processing. SAFETY: The extension rod diameter and other parts are precision ground. Accurate grinding can eliminate the outer diameter of the rod and the imbalance of the rod, improve the stability of cutting, and increase the safety during cutting. STRICT HANDLE: Various details of the product are carefully handled to ensure the stability and accuracy of the product. WIDELY USED: This chuck collet is for reducing the using of extended cutting tool, reduce the cost of processing, increase efficiency. Specifications: Material: 45# Steel 4mm Size: approx 40x35x16x4mm/1.57x1.38x0.63x0.16 inches 5mm Size: approx 40x35x16x5mm/1.57x1.38x0.63x0.20 inches 6mm Size: approx 40x35x16x6mm/1.57x1.38x0.63x0.24 inches 6.35mm Size: approx 40x35x16x6.35mm/1.57x1.38x0.63x0.25 inches Type: 4mm/5mm/6mm/6.35mm Note: 1.Please allow 1-3cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x ER11A Extension Rod