Transmission Fluid Temperature Is The Single Biggest Contributing Factor To The Lifespan Of Your Automatic Transmission. Having An Accurate, Realtime Measurement Allows You To Know When To Downshift Or When To Take Your Foot Out Of It. Whether You" Re Towing Or Simply Trying To Harness The Power Of A Built Or Boosted Motor, Autometers Mechanical Trans Temp Gauge Will Give You The Most Accurate Possible Measurement For The Exact Temp Of Your Trans Fluid. An 8" Capillary Tube With A 1/2" Npt Mounting Nut Is Included To Be Installed In Your Transmission Pan. An Optional Trans Cooler Line Manifold Is Available For Another Easy Installation Option.