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 users to accomplish jobs at hard to reach nuts and bolts without compromising the needed torque. A robust metal case is included for easy storage and transport.