A unique product for the Holley 4500's provides a low pressure area under the throttle plates for improved signal to the booster while assisting with reversion from the overlap of the camshaft by turning the air around as it is pushed up through the carb. The 7 degree taper and the sharp edge have been engineered to make the Dominator perform at its peak and to gain the most power from your combination. An additional benefit is that it serves as a safety plate and prevents the internal linkage from falling into the engine in case of separation. Clear anodized 1/2'' thick 6061 aluminum, available for 2'' and 2-1/8'' throttle bores. Installs with flat surface against carb, view shown is plenum (intake) side. Made in USA.