Corrosive resistant and laser engraved every 120 degrees. Extra recess depth, 30 degree flex angle and smooth collar design . SureGrip hex design drives the side of the fastener, not the corner. Made in the U.S.A.. Lifetime warranty15 piece set is made in the U.S.A., featuring the SK's High Visibility technology. The sockets are coated with a rust-preventative compound, which makes them exceptionally resistant to corrosive factors. In addition to the rust-preventative coating, the sockets are laser engraved every 120 degrees with extra-large markings for improved readability. 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. Extra recess depth and a 30 degree flex angle allow for improved access. SK's smooth collar design protects the user's hand while in use by preventing the pin from working loose. Sizes include: 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm Sockets. Packaged in a molded plastic case.