Engines Dont Like High Water Temperatures, Heat Is The Enemy Of Performance And Reliability. Keep Tabs On Your Temps With The Most Accurate, Quickest Responding Water Temperature Gauge On The Market. Autometers Advanced Bourdon Tube Meter Movement Provides Unparalleled Performance In The Most Demanding Applications. A 12" Capillary Tube And 1/2" Npt Mounting Nut Are Included.