This product was what I was looking for, but the hydrometer does not work at all, and generally the product is cheaply made - the plastic has a very cheap feel. It is quite frustrating that manufacturers choose to produce low-quality products like this. Make something well and charge me a few bucks more for it. I would prefer to pay $10-$12 or even $15-$20 for an excellent thermometer /hydrometer that is accurate and will last years, instead of "saving money" by paying $7 for a low-quality product that will only add to our overflowing landfills in short order. Manufacturers seem no longer to understand this concept.
I bought 2 the temp stays the same on them but the Humidity guide differs around 10 or so points ,, To me thats not the end of the world I can tell if its humid or not , I would prefer an easier ( larger ) temp scale though