Took two tries, but the second has worked fine. We went wireless the second time and that was simple, easy and about the same price. We used industrial velcro - comes as a hard block with hooks and super sticky felt strips. Three trips in and out of Saline Valley and no problem.
The first try taught us what to look for: LARGE display, easy to find light switch, simultaneous display of indoor and outdoor temperatures. Humidity display was also quite helpful because knowing the humidity and outdoor temperature made adjusting the Norcold fridge more accurate. Time is nice, but we could live without it. Oh, and choose a unit that uses standard AAA or AA batteries, that is, avoid Oregon Scientific and such.