Traditional incandescent lighting illuminates around the perimeter of the dialHigh Transfer Case Temps Mean The Difference Between Having 4Wd And Not Having 4Wd. Monitoring This Critical Parameter Ensures That Your Cooling System Is Performing Properly And Your Transfer Case Will Continue To Transfer The Power To All Of The Drivetrain. Highly Accurate And Durable Thanks To Autometers Patented Air Core Meter Movement, A Single Wire, 1 8" Npt Temperature Sender Is Included.