Made of chrome vanadium steel, heat treated to improve durabilityThe blackened phosphate coating prevents corrosion damage and is durable in useCan be used with pneumatic or electric impact wrench and hand ratchetsize: 1/4 inch, 1/2 inch, 3/8 inch Material:Chrome vanadium steelcolour:blackPackage Contents:3 x Ratchet wrench socketOnly the above package content, other products are not included.Note: Light shooting 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.