Screw driver bits set 10 pc. The tip of a screwdriver is thermally treated to increase the time of use. Built with special steel and cobalt coating is very stable and provides a rapid and efficient screw.The screws used for mounting on surfaces with different materials. Kit Contents: PH1,PH2,PH3, PZ1,PZ2,PZ3, Sx4.5,Sx5.Sx8, Bit Holder (plus 2) (two extra PZ2/PZ3 Driver bits 50mm)