Unless you are not able to afford a better tstat I would get a different one. I bought one of those once and it was dead within 3 months. It died in the on position. I was lucky and found it shortly after it started having issues so no harm was done. From that point on I would no longer recommend them.
I would get the best you can afford as it is the most important thing you are about to buy.
I like Herpstat and have 4.
http://spyderrobotics.com/home/products.html
Many also like these.
http://www.reptilebasics.com/thermostats