No-Slip design in forged cro-moly steel grips flats of fasteners not the corners . Lifetime manufacturer's warranty. 1/4" drive, standard length 6 point impact sockets Includes: 3/16", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 7/16", 1/2" and 9/16" in a molded storage tray