DUAL GAS FEED FUEL LINE WITH FUEL PRESSURE GAUGEFits Holley with 9-5/16 centers. This fuel line is not only great looking, but is also very functional. It incorporates a small 1 1/2" dia. fuel pressure gauge. The gauge is designed to read in 1/2lb. increments and has a range of 0-15lbs. Inverted flare female inlet thread size 5/8-18.