Feature: 1. The pliers are integrally formed with a large overall length and are suitable for installation on a knife sharpener. 2. The clamping force is strong and the clamping precision is 0.02mm, which is suitable for fine operation. 3. The opening precision is high, the thread size is standard, and it is not easy to fall off during installation and use. 4. Different size specifications have different clamping ranges, which are suitable for different clamping situations. 5. Made of high-quality metal materials, the hardness is HRC40-45, and it is not easy to be squeezed by the outside world. Specifications: Item Type: Pencil Sharpener Chuck Model: 3-9mm Grinder Chuck Hardness: HRC40-45 Clamping Precision: 0.02mm Clamping Range: Approx. 3mm/0.12in, 4mm/0.16in, 5mm/0.2in, 6mm/0.24in, 7mm/0.28in, 8mm/0.31in, 9mm / 0.4 inch Pliers Total Length: Approx. 122mm / 4.8in Diameter of Plier End: Approx. 20mm / 0.8in Tail Thread: M20 Tail Thread Length: Approx. 29mm / 1.1in Shank Diameter: Approx. 20mm / 0.8in Package List: 1 x 4mm Chuck Note: 1. Place each type of chuck into the corresponding diameter tool to avoid damage to the chuck because the tool diameter exceeds the size of the chuck model . 2. When changing tools, clean the impurities inside the liner in time to ensure the life of the chuck.