The 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.