I completed one testing at a setting of 90 degrees to see if the switch would functioned as intended. The switch performed but closed at 78.7 degrees and not the 90 it was set at. I will say that the heat coming off the generator housing could be hotter than my thermostat reader nearby so the open switch performed within tolerance, all things considering. Time will tell how close to the 90-135 degrees adjustable setting the switch will consistently perform. Most products are produced in China and their metals are not as good as American switches even though they are made to spec. Chinese metals are weaker in every way. Unfortunately, America doesn't produce much of anything and parts are not worth fixing seeing they are built so cheaply today. Overall, good so far and I would recommend this type of adjustable switch over a fixed temperature switch.