... head,Button head...Socket typesPhillip type,Pozi type,Eleven type,hexagonal type,Torx type,trangle type,slotted point type,square type,Combined type...FinishZinc plated,Nickel ... used in our products,Hexavalent chromium are accord with ROHS Standard.Weight Quantity of each plastic bag ... tighten the fasteners by wrench ,key ,bit and spanner.When head become thicker,and then the socket is much deeper ...