When used with a torque wrench enable you to reach inaccessible fasteners that a socket cannot reach. The additional 2"(50mm) length is added to the torque wrench length to calculate correct torque. SAE Torque Adaptor Sizes: 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4". Length: 2"(50mm).