Liquid-Filled Mechanical Boost Gauge;0 - 35 psi;Incl. 6 ft. Nylon Tubing; California Residents: WARNING Mechanical boost gauges have become the staple in boost pressure monitoring for all types of engines, gasoline, diesel, or otherwise. Ultra-precise bourdon tube meter movement ensures accuracy and durability not seen anywhere else in the industry. A simple 1/8 inch NPT pressure connection requires no electrical hookup for operation. Includes 1/8 inch NPT fittings and nylon line kit.