IRWIN Impact Performance Series Magnetic Nutsetters are built for maximum durability, performance, and long life with impact tools. They are designed to drive the fastener from the side, rather than forcing the corners to turn, maintaining the true shape of the fastener and dramatically reducing breakage and damage from stripping. The lobular design also provides more clearance on the corners of the fastener where paint build-up often occurs. They also feature powerful rare earth magnets that hold fasteners securely in place. They have a black oxide finish that resists corrosion and increases the life of the nutsetter. Plus, with a 1/4" quick-change shank, they're designed to work with all types of impact drivers, and also fit securely in standard drill chucks.