GEDORE vanadium steel 31CrV3, chrome-plated, 5 square sizes: 8.7, 9.5, 10.5, 11.5, 13 mm, 4 tapered sizes: 6.8-8.7, 10.5-13, 15.2-18, 16.5-19 mm, One screwdriver blade: 5.5 x 18 mm, Screwdriver blade 5.5x18 mm