Features and Benefits: Includes the following sizes: 5 mm, 5.5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm,13 mm, 14 mm and 15 mmForged from the finest chrome-molybdenum alloy steel, the best choice for strengthBlack oxide finish and has etchings for identificationIncluded in a heavy-duty blow mold case This is an impact socket set with 12-piece. Sockets are 1/4 in. drive and metric. Designed to tackle the toughest jobs with solid durability and keeps them pounding job after job. WARNING: This product can expose you to Nickel (Metallic) a chemical known to the State of California to cause Cancer. For more information go to www.P65Warnings.ca.gov.