Heat-treated, durable, high hardness, not easy to wear and tear.[Professional hex bit set is made of S2 alloy steel, excellent workmanship, tough as nails]The hardness can reach HRC62 degrees. The hex wrench set is suitable for electric drills with speed control, electric screwdrivers, hand screwdrivers. Please do not use drill bits on air tools, pneumatic drills, and electric drills without speed controls. Thanks to its durable construction and superior technology, the drill has a long lifespan.High quality and long lasting. The hex bit sets are clearly marked so you can quickly find the size you need. Easy to carry and use.The Hex screwdriver set is a bit magnetic to help keep the nuts and bolts on. Can improve your work efficiency.Colour:As ShownMaterial:S2 alloy steelSize:65mm:8.8 x 7.5 x 1cm 110mm:12.6 x 7.5 x 1cmPackage Contents:10 x 65mm Insulation bit10 x 110mm Insulation bitOnly 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.