27 piece set is made in the U.S.A., featuring an improved black coating retaining more rust preventative compound than black oxide. All the SK impact sockets feature the SK's SureGrip® hex design, which drives the side of the hex, not the corner. This not only provides increased strength, but also avoids the rounding of rusted or damaged fasteners, which can occur when using a sharp cornered hex tool.Neck-down design provides improved access over tapered designMade in the USA1" Drive Deep Impact Sockets - 7/8", 15/16", 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", 2", 2'1/16", 2'1/8", 2'3/16", 2'1/4", 2'5/16", 2'3/8", 2'9/16", 2'3/4"