Feekoon Thermostatically Controlled Outlet, Temperature Controller on at 15.8°F to 33.8°F, Cold Weather Temperature Controlled Outlet for Automotive Engine and Battery Heaters

I bought this to use in my small semi insulated greenhouse where I store a lot of potted plants. We had below 0 temps forecasted, and I wanted to add some heat, but not 24/7 if not needed.I plugged an LED nightlight in one plug, so I would know when it came on, and a heater in the other. It came on in the evening when the thermometer inside the greenhouse hit around 20, but I placed it in the coldest spot, so it was probably a bit colder there. It was not on in the AM when I checked. It did exactly what I expected, and I am happy with it it.

Bought 3 of these to use with hummingbird feeder heaters during our recent deep-freezing weather. We were under 30 degrees for several days. Plugged them into an exterior grounded extension cord in order to reach the heaters but they failed to work. Tossed all 3 into the freezer, waited 20 minutes and plugged them directly into a wall outlet and they worked fine but this didn't solve the heater problem. As both the heaters and extension cords worked together just fine, I ended up manually unplugging the heaters when temps rose above freezing, a chore I was hoping to eliminate.

Well the temp finally fell to 2 degrees and guess this outlet does not even work.. FAIL

It was supposed to come on at 15 Fahrenheit, but it did not. Simply useless for what I wanted it for.