Seeing The Exact Fuel Pressure On Your Vehicle Can Mean The Difference Between Extracting The Most Performance Safely And Expensive Failures. Autometers Mechanical Fuel Pressure Gauge Will Precisely Measure Your Exact Fuel Pressure At Levels Of Accuracy Previously Unheard Of Even In Professional Gauges. Designed For Carbureted Applications A Simple -4An Connection Makes Installation Easy. Dont Take Chances With Your Investment, A Precise Fuel Pressure Gauge Could Be The Cheapest Insurance Youve Ever Bought. For The Safety Of The Operator A Fuel Pressure Isolator Is Included.