Product review (5 stars): It was a bit tricky getting the controls to a perfect -4 degrees (I use a thermometer to measure the ...
I've owned this for 5 months and it has worked consistently.  I use it exclusively for freezing my breast milk in.  It was a bit tricky getting the controls to a perfect -4 degrees (I use a thermometer to measure the temperature), but I was able to tweak them to get it to that optimal temperature.  I believe the freezer goes down to -40 at the lowest setting, but perhaps it can go even lower when full.