WHOLESALE 10-Pc Universal spline socket set. Designed to fit many types of fateners: SAE, MM, 6pt, 12pt, Spline, external star, square. Size: 6 mm (1/4""""), 8 mm (5/16""""), 9 mm (11/32""""), 10 mm (3/8""""), 11 mm (7/16""""), 13 mm (1/2""""), 14 mm (9/16""""), 16 mm (5/8""""), 17 mm (11/16""""), 19 mm (3/4"""") Black manganese phosphate finish for extreme corrosion resistance.Illinois Industrial Tool Professional series tools