Features:The interface has a locking mechanism， built-have magnetic， automatically pop up batch headSuitable for drill， screwdriver， batch head and other to transferExtend all kinds of screwdriver bits， screwdriver head conversion useQuick release bit-fix holder fits directly into drill chuckFast， fastening， greatly improve work efficiencyDiameter: 1/4" hex shank (6.35mm)Length: Approx. 60mm/ 2.36"Package Included:1 x 1/4" 60mm Hex Shank Quick Release Magnetic Screwdriver Bit Holder