Seven sizes for external Torx(TM) bolts: E6, E7, E8, E10, E12, E14 and E16. The three smaller sizes are 1/4" drive; the four larger sizes are 3/8" drive. Sockets are made of special heat-treated alloy steel. Sockets are kept in a convenient vinyl holder. Made in Clarinda, IA, U.S.A.