3/8" Drive Impact Socket Set, 13 Piece, 6 Point, Standard Metric Forged from the finest Molybdenum alloy steel - the best choice for strength and durability. Designed to extend the life of fasteners. Features a radius corner design causing the socket to grab the sturdy wall, or flat, of the fastener instead of grabbing the corners. This results in less corner wear on the fastener. Lifetime Warranty -- full replacement.