Features:Made of lightweight carbon steel and chrome vanadium steel, compact and easy to carry.Extend all kinds of screwdriver bits, screwdriver head conversion uses.The universal 1/4-inch quick hex handle and 1/4 inch hex socket are suitable for most electric screwdrivers and drills.Small size allows you to extend your bit to any location to complete any work and can accommodate many tool kits.This connecting rod is made of carbon steel pipe which can disperse the magnetism, so lead to the suctionis weak. If need to absorb screw fastener, recommended to buy screwdriver bitwith magnetic.Specifications:Material: the handle is the chromium vanadium steel, the casing is carbon steelHex shank size: 6.35mm (1/4 ")Hex slot size: 6.35mm (1/4 ")Color(Optional): black knurling, black &white three troughLength(optional): 60mm (2.36 "), 100mm (3.93 "), 150mm (5.9 ") Suggestion: install on electric screwdriver, use it with screwdriver bit.Package Included:1 x Quick Release Screwdriver Drill Bit Holder