Made of S2 alloy steel which is anti-impact and tough, great wear resistant. Strong magnetic, each edge can be accurately locked screws, no damage to the screw and the screwdriver head. Fit for electric screwdrivers, hand screwdrivers, electric drills, air drills and so forth. Colour:Silver Material:S2 alloy steel Size:Inch drill: 5/64 inch, 3/32 inch,7/64 inch, 1/8 inch, 9/64 inch, 5/32 inch, 3/16 inch, 7/32 inch, 1/4 inch, 5/16 inch Metric drill bit: 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm Package Contents: 20 x SAE Drill Bit 20 x Metric Drill Bit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.