redpython, I was saying not to use an analog thermostat with a UTH designed for glass cages if you were going to use the UTH on a plastic cage.

Because it is only on/off, the UTH might reach excessive temperatures in contact with the plastic before the thermostat kicked it back off--as generally you will want to put the probe where the animal will be basking.

In general, it's just a bad idea to use a glass-tank-only UTH with plastic caging, but if you have to do it anyhow, make it as safe as possible.