It will but I wouldn't built a nice cage and go cheap on the tstat. If it were me I would go with a Herpstat4.

Flexwatt is a serious heating device and I wouldn't trust the hydrofarm with it. I bought one and if failed on others use them without issue but failing once was enough to turn me away from them. VE has a new entry level tstat that would be a better cheap choice.http://www.thevog.net/styles/smilies/TX.gif
I still would not recommend a on/off tstat and urge you to get a digital one that has the proportion option.