Heating options for leo rack

[Star1]

My boyfriend is going to build me a leopard gecko hatchling rack, and I'm not sure how to heat it. I have one that someone else built and they used heat cable, but I don't like it- even with a thermostat the temperature fluctuates a bit. It's been as low as 78 and as high as 101 in the same day with only changing it a degree or 2. It's not my thermostat either because I was using it on something else and had no problems. Flexxwatt doesn't come in good sizes for what I want- 3" seems too small and 11" is too large. My plastic shoe boxes are 11.5"
What other options are there?

 

[Caleb C]

Thermostats are supposed to make a limit to the temp, and a good one will cost around $100. The most common is flexwatt, and its also the most trusted. I think you should email lllreptile or beanfarm or someone that sells flexwatt about it.