Product review (3 stars): can't complain - works well at 350 degF and withing 10% at 250/450 degF...
I had to replace the thermostat in an oven.  I used an oven thermometer to find that the oven was reading about 100 degF higher than the set point.  I googled and thought that the thermocouple needed to be fixed but when I started disassembling the temperature probe, I discovered that it was connected to the knob.  I then googled the part number on the knob/sensor and found it was a thermostat.  You basically have to take apart the oven to replace the thermostat and feed it through all the tight spaces but once it was replaced and reassembled, it worked pretty good.  At 350 degF it was holding pretty consistently but and within 10% at the 250 degF and 450 degF.  Can't really expect it to do much better than that.