This liquid-filled gauge is calibrated 0-100 psi with 6' nylon tube and 1/8" and 1/4" NPT fittings. Technical Notes: These easy-to-read Professional Competition gauges with a matte black face and contrasting white numerals and GM Performance Parts logo are the ultimate in precision and durability. The liquid-filled temperature and pressure gauges dampen vibrations for accurate, steady readings. The black satin-finish bezel (213/16" diameter) reduces glare. They fit a 25/8" mounting hole and include 12-volt lighting and mounting hardware.