Features and Benefits: Made of heat treated chrome vanadium steel for durability Features high chrome finish which protects the tools from harsh working environments found in today s workplace Marked with part number and size for ease of use Lifetime warranty Made of heat-treated chrome vanadium steel for durability. Our sockets feature high-polish chrome finish which protects the tools from the harsh working environments found in today s workplace. Lifetime warranty. All sockets are marked with part number and size for ease of use.