I had one of those for a hot minute. 38 eggs were killed due to temperature spike to 110 degrees overnight. I renamed it the "murder-bator" and sold it ASAP. The only success I had controlling temperature is by placing an Allen wrench into the knob which allows the ability to move the knob a tiny bit at a time. Then you have to give it several hours to stabilize before making another adjustment. And the light has a bit of a delay and doesn't come on immediately when an increase is made. I hated it and will never recommend to anyone. Others love theirs and have had very successful hatches with it. I wish you luck.
