Ok

Works in our millivolt floor furnace application well in that when it connects the two wires the furnace turns on and when it opens the furnace turns off. The only issue I have is that the control is so course. When set to 75 for example it stays on until the air temp is 80 then turns off. When the air temp reaches about 68 it turns back on. It rocks between the 10-12 degree range. I find I have to get up and turn the temp down when it is heating then turn it back on again when the place cools down. Good exercise. But, that kind of defeats the purpose of the contraption. Other than the range of control, this works well and is a very easy install. I think I am going to try one of the electronic ones that uses a calibrated thermistor rather than the bimetal to see if I can get control as good as the old Mercury thermostat. That one was /-2 degrees for a temp band of about 4 degrees. The electronic one requires batteries but claims /- 1 degree control. That might cause a furnace oscillation problem though. It is tough to beat the old Mercury devices.

Easy connect (2-wires) Have to take back off and adjust brass part as it takes too long for the furnace to come on again.

No problem installing, two wires one red the other white