The standard in the industry, AutoMeter?s Mechanical Boost/Vac gauges have found their way into more builds than any other. Using a patented, high precision bourdon tube meter movement, there isn?t another gauge on the market that can lay claim to the levels of accuracy or durability you?ll find here. A simple 1/8? NPT pressure connection requires no electrical hookup for operation. Appropriate 1/8? NPT fittings and line kits are available separately.