Umm from the best of my knowledge zoomed UTH are for glass containers only. I have some Vision cages left over and wanted to use them and had a very hard time finding UTH in a pet store that will work for plastic. I would suggest some kind of Flexwatt hooked to a thermostat will be ideal for you. Or you can put stick the heat pads you are using to the back SIDE wall of the plastic, that will not burn your container as bad as the bottom.