This nut driver is designed to drive fasteners from the side, rather than forcing corners to turn, maintaining the true shape of the fastener Lobular design provides more clearance on the corners of the fastener where paint build-up often occurs. 1/4-inch quick-change shank, they're designed to work with all types of impact and rotary drivers Uses a rare earth magnet that is 4 times more powerful than common magnets Backed by the IRWIN lifetime guarantee