RV Mirror w/Thermometer, compass, & auto-dimming. Complete with sensor, & mounting button, tested working.
"If the temperature sensor is short- or open-circuited, the display will read SC or OC, respectively, instead of a temperature. If the temperature drops below 3.3°C (38°F) or is below 3.3°C (38°F) upon power-up, the display will alternate between displaying "ICE" and the temperature. The display will alternate every two seconds for a time of one minute."
Compare to:
http://www.mitocorp.com/auto-dimming-mirrors.html
http://www.aztrucks.com/product.asp?Product=166
For calibration, see this: