IHUMI 49-Percent Humidity Control Packs-64 Gram 4 Pack-All-Natural 2-Way Humidity Control Packets Keep Flower,Herb,Medicine Fresh

Very convenient. Small units. Hard to use multiple pads in multiple guitar cases & know when they’ve lost their “juice”. I’m going back to Bovida Humidipacks.

I'm not sure there is any real moisture retaining substance in them. They had zero effect in use as measured by a hygrometer. Total con job.

I put one of these in a cabinet that houses my vitamins and medicines. I am often concerned about their being stored in a place that has the right humidity level, so these humidity control packs seemed like the perfect solution. Unfortunately, I don't think they work very well. I placed a small hygrometer beside the pack in my medicine cabinet and took a picture. The hygrometer read 66% when I put them in there, as shown in one of my photos. Another photo shows the reading about five days later when I checked back. It says the relative humidity is 71%. Now, it is perfectly possible that my hygrometer isn't as accurate as it ought to be, and in fact, I checked it against a couple of other humidity measurement devices. It did differ from them slightly, but consistently so, and only within about 5 percentage points. So it seems like this humidity pack didn't bring the relative humidity in my medicine cabinet anywhere near the 49% it promises to do. Unless there's something I don't understand, it looks to me like these just don't work.By the way, another problem with these humidity packs is that the outer packaging had a sticker that had been placed right over the directions for use. I tried to peel it back, but couldn't remove it without damaging the print behind it, so I couldn't fully read the instructions. Maybe there was something there I missed that might have made the difference in my little experiment. Who knows? And that's the problematic point.I hope my experience with this product might help YOU make a more informed purchase. Happy shopping!

When I grabbed this I thought it was to help capture the moisture and humidity in a room, but these are for much smaller spaces. I am not sure if I am using this correctly but I've been using these under my kitchen sink area where it gets a little dank and funky. Certainly can't hurt.

These humidity control packs work very well, I've been using now for almost two months. Average life expectancy is approx 3 months, I've read. You can get different sizes and levels of humidity. IHUMI has a very handy chart to help determine which percent is best for you. These are for guitars.I agree with other reviewers that there should be more than one indicator (pink dot) with each package. These measure 4" long x 2.5" wide, something to keep in mind when buying, they eat up storage in glass containers. But it's worth it, these make a big difference in my storage.

I followed the instructions and used the moisture indicator and according to it, I was able to tell when it was time to exchange

I don't understand why there are 10 envelopes but only one card with the pink dot . . . you can only use one at a time or what???