For Pozidriv head screws with thread drive.For optimized use in stationary screw system.K19PZD-2NF: Screw thread 10/32” UNF.K19PZD-2M5: Screw thread M5.DUOFAST automatic screwdriver, on BOSCH, FEIN and MAKITA screwdrivers or HOLZ-HER magazine screwdriver.High performance alloy steel.Steel-grey, greased finish.Packed individually in a plastic bag