I initially bought a version of this compass without a mirror.  It is a good compass, but I decided it would be easier and more accurate to read if I had bought the version (Suunto MC-2DLIN Compass) with the mirror.  I like this mirrored version so well that I bought another just like it as a back-up. This compass is easy to get a reading using the mirror.  The scales provided on the see-thru base are nice and adjusting for declination is very easy; just flip the compass over and using the supplied tool, make a slight adjustment (East or West, as apprpriate) and then you are true North!  I had to adjust for 7 1/2 degrees West declination and it was easy to do.