Forged from the finest chrome molybdenum alloy steel - the best choice for strength and durability. Radius corner design-to extend the life of the fastener. Ideal for working in tight areas. Included in a heavy molded storage tray. Fully guaranteed No doubt, Sunex tools offer one of the most complete and toughest Impact Socket lines around. This 3/8" drive, universal impact socket set designed to tackle the toughest jobs with solid durability and keeps them pounding job after job. Also each socket features a radius corner design, causing the socket to grab the sturdy wall of the fastener instead of grabbing the corners, resulting in less wear on the fastener. This set includes the following sizes: 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4".