Klein Tools' 7/16-Inch Hollow Magnetic Color-Coded Hollow Power Nut Driver was designed with the professional in mind. The 3-3/4-Inch (9.5 cm) hollow core facilitates work on threaded rod by enabling easier access to nut. Made of high-grade impact steel and is color-coded for easy identification. The nut driver contains Rare-Earth magnets to securely hold fasteners, and is also extra long for greater reach. 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.