3Pcs 60/100/150mm Head Batch Rod 1/4 Inch Hex Chuck Quick Release Self-Locking Screwdriver Magnetic Drill Bit Extension RodsFeature:The interface has a locking mechanism with built-in strong magnet. Suitable for electric drills, screwdrivers, air batch, etc., to prolong the conversion of various bits and screwdrivers; Quickly; Greatly improve work efficiency. Application: Labor-saving accessories for electric hand drill and electric batch, the diagonal diameter of the hexagonal chuck is 1/4 inch or 6.35mm. The inner hexagon has strong magnetism. Specification: Red R groove post: 60mm/2.36in, 100mm/3.94in, 150mm/5.91in (three lengths)Package Size: 170x60x1 5mm/6.69x2.36x0.59inNote:Due to the different monitor and light effect, the actual color of the item may be slightly different from the color showed on the pictures. Please allow 1-2cm measurement deviation due to manual measurement.3 X Extension Rods