In my opinion they are another chepo Made in Tawain/China piece of garbage.

When I first started keepeing snake I went through 3 of them in less than 2 months, they were extremely inaccuate and at the end the bad experience I got a Ranco which still works fine today(many years later). In the long run the Ranco was cheaper because I didnt have to keep replacing it.

I found that the Chinese ones come in several different name brands(depending on who subcontracted them) and colors or stickers but are essentially the same pet store cheapo T-stat.