Designed by Dynojet for Cobra Carburetor recalibration kits tuned specifically for cruisers using Cobra Boulevard exhaust and stock or aftermarket air filter Provide improved throttle response and pulling power throughout the rpm band All necessary performance components and step-by-step instructions are included for each model; CAUTION: Cobra's performance jet kit is not emissions-approved. It is intended for racing applications only. Legal in California only for racing vehicles that may never be used on a public highway.