The BlueSpot 4 PCE Impact Socket Adaptor Set (3/8", 1/2", 3/4")is manufactured from chrome molybdenum, this makes it suitable for high impact use. The blackened phosphate coating protects against corrosion. The comprehensive set of impact adaptors is ideal for use on all types of impact tools.Package Contents - 3/8" (F) x 1/2" (M), 1/2" (F) x 3/8" (M), 1/2" (F) x 3/4" (M), 3/4" (F) x 1/2" (M). Manufactured from chrome molybdenum for increased durabilityBlackened phosphate coating protects against corrosionComprehensive set of impact adaptors for use on all types of impact tools