These Needle Valves Are Special Made With A Lightweight Glass Ball, Eliminating Flooding Caused By The Overweight Steel Ball That Our Competitors Sell. The Glass Is Less Than 1/4 Of The Weight Of The Steel Ball Which Allows You To Raise The Fuel Pressure. We Have Run Up To 9 Pounds In Our Own Cars. Sold In Pairs. Made In The U.S. By Jaycee!