HCA: Hermit Crab Association

I thought I had all the things I need for my hermit crabs in the tank..until I relized that I didnt have a temperature and humidity guage!!
So I went ahead and saw all reviews on all different types. zoomed, digital monitors...
I want to get something that will last long and somethign that works..(with a good price)

What do you use/what do you recommend?

I have this and really like it:

http://www.amazon.com/gp/aw/d/B0013BKDO ... SY200_QL40#

I've used both analog and digital brands. Both will need calibrating to check their accuracy and in my experience, both can quit working after a time. AcuRite digital thermometer/hygrometer is a great price. Mine was reading 10% off and the display is a bit messed up, but it's still usable a year later. With analog ones I like the All Living Things brand best simply because they can actually be adjusted and seem to last a little longer than other analog ones that I've tried.

These are the ones I'm talking about.

(not my photo)

Thanks!