Review on 🌡️ Humidity Indicator Card with 3 Dot Accuracy - 30%/40%/50% - MS20003-2 by Brandon Wong

These things work great in my attic storage boxes that I use with desiccant packs. I cut out a small rectangle on the sides of the containers and use clear tape as the window. I then used a small strip of tape to hang the indicator inside. Just make sure you don't tape off the whole card or the indicators will never show internal moisture! The gauges revert to blue once the humidity falls below acceptable levels, but that takes longer than I expected.