GE started developing and testing a new type of combustor called the Twin Annular Premixing Swirler combustor, or "TAPS", during the Tech 56 program. This design is similar to the double-annular combustor in that it has two combustion zones; this combustor "swirls" the flow, creating an ideal fuel–air mixture. This difference allows the combustor to generate much less NO"x" than other combustors. Tests on a CFM56-7B engine demonstrated an improvement of 46% over single-annular combustors and 22% over double-annular combustors. The analytical tools developed for TAPS have also been used to improve other combustors, notably the single-annular combustors in some CFM56-5B and -7B engines.