ITEM NAME:18 mm Gear dia 6 mm Pilot Spanner Drill Chuck Tool Black Y5J7 18 mm Gear dia 6 mm Pilot Spanner Drill Chuck Tool Black Y5J7 A chuck require a key to provide the necessary torque to tighten and loosen the jaws. A chuck key is perfect for tightening and loosen. Item Name: Drill chuck Pilot Diameter: 6mm / 0.29 inch Gear diameter: 18mm / 0.7 inch Total size: 80 x 42mm / 3.1 inch x 1.7inch (L * W) Teeth: 12 Color: Black Material: metal Weight: 44g Scope of