Range 0 - 40" H2O. Designed to monitor the condition of your air filters. Programmable "Change" light alerts you when to change your filter. Normal is a programmed setting of 16" or 18". Once the new filter has been installed, the gauge will re-set itself. 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.