Item Type: Drill Bit Extension Set Material: Chrome vanadium steel Purpose: Drill accessories Hex Shank Specification: 1/4in Quick Chuck Clamping Range: Approx. 0.3-3.6mm / 0.01-0.14in Quick Chuck Surface Treatment: Nickel plating1[POWER TOOL PARTS] Including 3pcs 1/4in hex shank drill extension rods and a quick drill chuck, often installed on power tools to use. 2[MAGNETIC SOCKET] The holes at the bottom of these drill extension tools are magnetic, with locking mechanism for safe operation. 3[DRILL QUICK CHUCK] The drill bit quick chuck can easily convert the cordless electric screwdriver into a drill bit, improving work efficiency. 4[EXCELLENT MATERIAL] The extension rod tool is made of chrome vanadium steel, heat treated to increase the hardness and wear resistance. 5[CLAMPING RANGE] The clamping range of the quick chuck is 0. 3?3. 6mm, which is suitable for more clamping projects. 3 x Hex Shank Extension Rod 1 x Quick Drill Chuck