Product review (5 stars): VERIFIED: Able to convert to Fahrenheit - BUT...
There are TWO different versions of the circuit board.  BOTH are able to be modified to display Fahrenheit.
BOTH require you bridge two points.  The one pictured shows a single 2-pad and a single 3-pad.  The other version of the board has only a 3-pad and you bridge "F" to the common center pad for THAT one.  THIS one, you bridge the 2-pad.  Very simple for those who work with electronics.  NOT to be attempted by accountants, actuaries, librarians... etc.  ;-)

I bought 4 and they are all within .5 degrees of each other.  For $2.50, I'm NOT complaining.  I have 2 more on the way for a total of 6