Description: With the self-locking design, the extension rod will automatically lock when the screwdriver head with hexagonal handle is inserted. And it has magnetism, which can firmly absorb the screwdriver bit. Extension rod can be used for the transfer and quick change of imported and domestic 1/4 electric screwdriver, manual electric screwdriver, electric drill and other tools. It is constructed of alloy material. There are 3 sizes for you to choose from. It is suitable for household, industry, workshop, factory, etc. And this extension rod can only hold a single-ended batch, but not a double-ended batch. Item Name: Bit Extension Rod Material: Alloy Features: Different Sizes, Fine Workmanship, Durable Size Details: 6cm, Length: 60mm/2.36"(Approx.) 10cm, Length: 100mm/3.94"(Approx.) 15cm, Length: 150mm/5.91"(Approx.) Shank Diameter: 0.635cm/0.25" (Approx.) Hole Diameter: 0.635cm/0.25" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Bit Extension Rod