I didn't see that. I just saw that the dimensions were too small to fit a 6 qt box so I stopped reading. There must be a switch built into it to reverse the polarity of the thermo-electric chip, but I still would also not trust the thermostat that's in it. With my wine cooler I had to cut the wires from the transformer and reverse them manually.
The thing is, the chips use regulated 12v, so you would either have to trust the thermostat that's in there or use an on/off thermostat. You can't use a proportional thermostat, and any fan that's inside it would stop running every time the heat switched off. So it's basically an expensive 20qt cooler that would need to be modded the same as a $15 plastic cooler in order for it to safely hatch 1-2 clutches of eggs.