Solid screwdriver with sensitive trigger switch that allows precise control of speed speed This makes it easy to set screws of different sizes or drill into metal without having to point the hole A planetary steel gearbox with a tooth hardness of 53-56 HRC guarantees the durability and power needed for use with pen drills The screwdriver can be used for non-impact drilling in brick with universal drills, and even in concrete of class C 16/20 (e g with the Sthor 21690 8 mm drill).