These replacement bits work with Klein's HVAC 8-in-1 Slide Driver screwdriver/nut driver (32596) and 11-in-1 multi-bit screwdriver (Cat. No. 32527). The double-ended Schrader Valve Core tool and 1/8-Inch (3.2 mm) slotted bits are designed for precision work. Made of the highest quality tempered steel, carefully heat-treated for maximum strength, and precision milled to fit screw openings securely. 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.