Pro-Series Adjustable Secondary Linkage Kit for all Holley Double Pumper, HP, and Ultra XP carburetors.; Featuring Stainless Steel construction and a lightweight yet rugged design, it provides a bulletproof method of adjusting secondaries on all Double Pumper, HP, and Ultra XP carburetors. It allows user to pick between 1:1 or progressive secondary ratio. Kit provides infinite adjustment of secondary throttle blades for maximum horsepower output.;.
