This SSF tool is a significant improvement over the decoding tools that have been on the market for decades. While it can be used in the same manner as the old style tools, the inclusion of a small notch at the tip allows the user to manipulate the test bar found in the most common four dial combination locks. When used properly, this can cut the decoding time in half. This notched decoder is 0.006" thick. Made in the U.S.A. What is SSF? SSF stands for small standard format. All SSF tools feature a compact and sleek design that folds conveniently into various key management systems. They can also be riveted together to keep their profile as minimal as possible. These tools can all be integrated into one system giving you a very capable multifunctional tool in one complete package.