Edelbrock's AVS2 #1901-CP with Electric Choke is a special Chrome Plasma finished 500 CFM street carb with annular flow booster technology for near-EFI-like drivability that you can feel as soon as you step on the gas. The AVS2 1901-CP features an annular ring with eight evenly spaced orifices replacing the standard single brass tube (down-leg) fuel feed. The AVS2 booster ring distributes fuel into the airflow stream with an even spray to eliminate flat spots and greatly improves throttle response in the low-to mid-RPM range without sacrificing top-end power. The Chrome Plasma finish is applied is a 7-stage process to ensure the most durable and brilliant finish possible. The durable AVS2 is unaffected by engine backfires since there are no power valves to blow out. For fast and simple part-throttle tuning, metering rods and springs can be changed in seconds without carburetor removal or fuel draining. AVS2 carbs have the unique ability to hold a tune when compared to other carburetors. Your tuning and adjustments stay unchanged, so performance remains consistent. Updated primary and secondary booster clusters in the AVS2 offer the most accurate and up-to-date calibration available for today's fuels and octane levels. Additionally, the unique Qwik-Tune secondary air valve allows for limitless calibration of the secondary circuit. Adjustments can be made with simple hand tools in seconds to suit your application. AVS2 Carburetors feature a two-piece design for easy tuning that allows you to make float level adjustments or replace internal components without draining the carburetor or removing it from the engine. The 1901-CP AVS2 500 CFM is manufactured by Edelbrock in the USA.