Thunderjet's patented third fuel circuit has a built-in air correction system that permanently solves the problem of poor midrange performance and/or a too lean condition on the top end. The system operates over a wide range of altitude and atmospheric conditions and can be installed on all S&S Super B, D, E and G models as well as Bendix/Zenith and Keihin carburetors. Available in Red, Blue or Black anodized versions.

Note: S&S Super E and Super G carburetors need to be rejetted.