12 piece, jumbo hex key set, sets consists of: metric sizes: 8mm, 10mm, 12mm, 14mm, 17mm & 19mm, sae sizes: 3/8", 7/16", 1/2", 9/16", 5/8" & 3/4", includes blow mold storage case, heat treated, chrome vanadium steel, black oxide finish resists rust & corrosion, ideal for use on large machinery.