Forged from the finest chrome molybdenum alloy steel - the best choice for strength and durability. Radius corner design - to extend the life of fasteners. Standard drive extension impact socket. Fully guaranteed No doubt, Sunex tools offer one of the most complete and toughest Impact Socket lines around. This 1/2" standard drive, impact socket extension is designed to tackle the toughest jobs with solid durability and keeps them pounding job after job. Also it 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.