Chrome molybdenum alloy steel for long life. Designed with radius corners, this allows it to grab the sturdy wall of the fastener instead of grabbing the corners. Industrial strength, double latch blow mold case. Fully guaranteed No doubt, Sunex Tools offers one of the most complete and toughest Impact Socket lines around. This 9 piece 1" drive, standard jumbo impact socket set tackles the toughest jobs with solid durability that keeps them pounding job after job. The design results in less corner wear on the fastener. All are forged from the finest chrome molybdenum alloy steel - the best choice for strength and durability. The following sizes are included: 1", 1-1/8", 1-1/4", 1-3/8", 1-1/2", 1-5/8", 1-3/4", 1-7/8", and 2".