The standard in the industry, AutoMeter's Mechanical BoostVac 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 18 NPT pressure connection requires no electrical hookup for operation. Appropriate 18 NPT fittings and line kits are available separately.