Each spanner features the patented ANTISLIP design and TORQUEPLUS fastening system to make tightening a breeze and limit potential damage to fasteners. Sizes: 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8, 15/16, 1". Materials: chrome vanadium.