This set is consisted of 6 most common sizes of deep and 6 standard sizes of impact sockets. Made of high-grade Chrome Molybdenum alloy, these black manganese phosphate finished and life time warrantied impact sockets are meant to last for generations. Built for strength, rigidity, wear resistance, corrosion resistance, and toughness, professional mechanics can rely on them to constantly deliver quality work results. The deep design allows professionals to accomplish jobs at hard to reach nuts and bolts without compromising the needed torque. All 12 sockets are size-orderly placed on a strip of chrome finished premium rack for easy size selection and effortless storage.