High Quality:Magnetic Bits Made Of Cacium Zinc Phasphized S2 Steel Surface For Optimum Strength And Longevity. Perfect For DIY Projects Household Maintenance And Repair, And So Much More.Accurately Machined :CNC-Machined Bit Tip For Precise Fit In Screw Heads For Reducing Cam-Out,1/4 Inch Hex Shank Fit With Most Of Hand Tools And Power Tools.