Features and Benefits:Includes: Standard and Deep 5/16″ to 3/4″ and 8mm to 19mm; Universal 3/8″ to 3/4″ and 10mm to 19mm; External Star E5 to E16; Star T20 to T55; 3″, 5″, 10″ and 15″ Extensions, 3/8″ Dr. Impact JointForged from the finest chrome-molybdenum alloy steel, the best choice for strengthRadius corner design extends the life of fasteners; design drives the side of the fastener instead of the cornerBlack oxide finish and has etchings for identificationIncluded in a heavy-duty blow mold case This is Master Impact Socket Set with 80-piece. Sockets are 3/8 in. Drive. Set Includes the most popular 3/8 in. drive metric and SAE impact sockets in one convenient set.