Heat treated for maximum durability Product Features:Bits made of S2 steel for strength and durabilityHard stamped size markingsBright, full polish chrome finish easily wipes clean and resists corrosionIncludes socket rail for storage and organizationSizes Included: 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 3/16, 7/32, 1/4, 5/16, 3/8