Screw driver bits set 37 pc. The tip of a screwdriver is thermally treated to increase the time of use. Built with special steel is very stable and provides a rapid and efficient screw.The screws used for mounting on surfaces with different materials. Kit Contents :23x25 mm. PH2, PH3,PZ1,PZ2,PZ3,R1,R2,R3.Th8, Th10, Th15,TH20,Th25,Th27,Th30,Th40.