Chrome molybdenum alloy steel for long life Ideal for work in tight spaces Reduces wear on fasteners Industrial strength, double latch blow molded case Set includes: 1", 1-1/16", 1-1/8", 1-3/16", 1-1/4", 1-5/16", 1-3/8", 1-7/16", 1-1/2", 1-9/16", 1-5/8", 1-11/16", 1-3/4", 1-13/16', 1-7/8", 1-15/16" and 2".