Used to build into a custom made exhaust system. Will increase torque by preventing exhaust waves entering the combustion chamber for a more positive cylinder fill. Stainless FEULING AR (Anti-Reversion) Chamber; Inlet 1.750"; exit 1.875"; 3.250" OAL Over All Length. Brushed finish. Includes Feuling AR badge. For use with a custom made exhaust; chambers must be fabricated into a system. Sold Each. AR Chambers. (Patent # US 4206600 A & 6336471 B1): Our patented Anti-Reversion technology transferred from our performance automotive development dating back to the 70’s. Designed to increase power; throttle response and fuel economy as well as reduce carbon deposits and cylinder temperatures. This is achieved by the overlapping bulb chamber inside that traps negative exhaust waves carrying heat and spent gases. By blocking these waves we also reduce exhaust gas from re-entering the combustion chamber; allowing for a more positive intake charge and crisper throttle response. This will also allow for a leaner tune increasing fuel economy. Note: Special Order Product only. To order please contact your MCS sales representative.