Monitors crutial air brake lines. Range is 0 - 100 PSI. One high accuracy external PSI sensor and cable included. Red, Blue, or Green LED display. Mounts in a standard 2-1/16" hole. Limited lifetime manufacturer's warranty. Made in the USA.  

NOTE: This gauge fits Peterbilt and Kenworth models; 2005 and older. Also fits Freightliner, International, Mack, Western Star, and Volvo models with 2-1/16" gauges on the dash.