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 . 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: 10 x SAE Drill Bit 10 x Metric Drill Bit Only the above package content, other products are not included. Note: Light 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.