Best Bit for Tight and Awkward Spaces：Yosoo extension bits can be attached to drill, impact or multi bit screwdriver. It bends, twists, and turns to get into the tightest and awkward spaces with ease Flexible Shaft: Connection hex shank drill site size 6.35mm (1/4) Connecting parts of the batch Hex size 6.35mm (1/4） Safe: Flexible out shield protects your hand while inside shaft rotates. Great for attaching to your power screwdriver. Attaches easily and stays secure until you remove it Applicability: It is an important tool for hardware maintenance and repair, including computer chassis, electrical cabinets, furniture, electrical appliances, etc. What You Get：Yosoo Flexible Extention Screwdriver Drill Bit Holder, Yosoo worry free guarantee and friendly customer service, Weight: 0.1 pounds, Manufacturer: Yosoo