This is our most popular EAS accessory and allows the average diesel truck owner to monitor Exhaust Gas Temperatures from their device on the dash. The external temperature probe must be installed in the exhaust manifold for the most accurate temperature readings. The closer to the combustion chamber, the better. Most applications will require the manifold be drilled and tapped to 1/8-NPT (bit and tap not included). Manifold fitting, probe, wiring, and EAS starter cable is included.