Autometer American Muscle 2-1/16in Full Sweep Mechanical 30 In Hg Vac/30PSI Boost Vacuum GaugeThe Standard In The Industry,Autometers Mechanical Boost Vac Gauges Have Found Their Way Into More Builds Than Any Other. Using A Patented,High Precision Bourdon Tube Meter Movement,There Isnt Another Gauge On The Market That Can Lay Claim To The Levels Of Accuracy Or Durability Youll Find Here. A Simple 1 8 Npt Pressure Connection Requires No Electrical Hookup For Operation. Includes 1 8 Npt Fittings And Nylon Line Kit. Installation Instructions