I got some questions about them, I honestly really didn't even knew they existed until I read another post about temperature. I would love to protect my new Fender(most expensive bass I have) the best I can. I stays inside the hardshell case at all times when not in use. My room almost always stays between 60-70 degrees. But now here in CT we have to crank our heaters on since its starting to get somewhat cold. Heater comes on humidity goes down. So are they really worth it especially in the northern parts. When I was searching I saw a post that a bass got damaged due to having one. I just want to protect my bass the best I can. Last winter when I had my Ibanez's they would need to be tweaked a bit every few weeks, maybe thats because the quality isn't as good.