Heat-treated chrome vanadium steel. Chrome-plated for durability and long life. Black chrome coating for a great look and an easy find in the tool box. T-handle has ball bearing detent socket holders on each leg. Also has a 1/4" drive swivel for access to tight spaces. Comes with sizes 5/16", 3/8", 7/16", 1/2" and 9/16". Manufacturer's lifetime warranty.