Phillips SET: This set includes 2 -piece 2 In,2 -piece 3.5 In (PH2),the size is printed in white, which can be quickly identified | Drill bits made from high quality S2 steel material with sturdy hardened,tempered construction, suitable for industrial use | Strong magnetic and high precision. each edge can be accurately locked screws, no damage to the screw and the screwdriver head | Torsion zone to absorb torque peaks to avoid breakage. 10 times life expectancy versus standard bits. For impact driver, drill and screwdriver | Widely used in home repairs, automobiles, woodworking and other screw driving applications