Product review (5 stars): Exactly what I ordered, EDIT: With great customer service!
It's a small thing that measures temperature and humidity, exactly what I needed. It works well, comes with a battery already in and running. It makes noise when you shake it, which isn't great, but I don't shake it often, so it's not an issue at all.

Edit: the seller contacted me about the "issue," offering to replace the product. It hasn't been any problem, so I'm going to spare the trouble, but the customer service is absolutely fantastic. It certainly earned the extra star. I've never purchased from a company so eager to ensure every customer is 100% satisfied.