Klein Tool's 5/16-Inch (8 mm) Keystone Screwdriver with 6-Inch square shank is designed for the most demanding uses. It has a cushion-grip handle for greater torque and comfort. Meets or exceeds applicable ASME / ANSI specifications and has Tip-Ident that quickly identifies the screwdriver type and tip orientation. Features 5/16-Inch precision-machined keystone tip. Screwdriver with 6-Inch square shank, has cushion grip handle. Tip-Ident makes identification of screwdriver type easy. Internal flanges inside handle provide solid, twist-resistant blade anchor. Special heat-treated shafts. Precision-machined tip for exact fit. Meets or exceeds applicable ASME / ANSI specifications. Tip-Ident quickly identifies the screwdriver type and tip orientation. For more than 160 years, Klein Tools has manufactured premium-quality, professional-grade hand tools that deliver the performance, durability and precision needed to get the job done right. Our family of engineers, workers and craftsman continue to put six generations of expertise into every tool we create by using only the highest quality materials, superior workmanship, and keeping manufacturing as close to home as we can. Klein isn't just the name of our company, it's also our family name. And since we're an American company that's family-owned and family-run, you know you can count on us to be here tomorrow. Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day ... Since 1857.