Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: Is it safe to have one of these inside a travel humidor inside a checked baggage on the plane?
Document: Just a little warning about these. They work great, but be careful. Before I bought a travel humidor, I got in the habit of sticking a few cigars in a ziploc bag with one of these. That worked fine, until I left them in the car overnight. Some moisture condensed inside the bag, got the plastic tube wet on the outside, and osmosis drew the solution through the plastic and onto my cigars. Completely ruined. So don't do something stupid like that, and you should be fine.
I bought one of these for a small humidor, and activated as per the instructions. It seemed to hold 67% humidity for about two weeks, and then the level fell quickly to 59%. I checked the beads and added more water, but the level didn't come back up. I will probably buy one more just to see if two will hold the humidity level where it needs to be.
I have a very small humidor (can hold maybe 10 cigars). The stock humidifier was unreliable, and I discovered the gel type products that come in a container. Unfortunately, they're too big for my humidor -- especially with cigars inside.The Drymistat is ingenious. If you have room for one more cigar, you have room for this humidifier. After just a couple days in my box, the humidity was stabilized at 70 percent.
The swelling crystals holding a blend of propylene glycol and water are an ideal way to supply moisture inside your humidor. The blend will evaporate only the water to keep your humidor protecting your priceless cigars, but also it will tell you when to replace it and in what amount, the propylene will avoid yeast and fungi from developing and will let you use tap water for replenishing the one lost from the tube to keep your humidor working properly. Each tube is designed adequately and will last for at least a year.
Simple and easy to use - just add distilled water, wait for it to be absorbed, and drop into the humidor. You'll need several of these if you have more than a small humidor, as an individual tube is only good for about 25 cigars. One of these would be ideal for a travel humidor.
It works well, easy to use. One tube doesn't provide enough humidity to keep my 25 cigar humidor in the ideal range. Probably would work better with multiple tubes. Does work very well in a travel sized humidor.
I always had trouble keeping my cigars fresh and properly humidified, but the DryMistat has solved all my problems. One tube had my travel humidor, which lives in my truck, up to 70% humidity within a day and has kept it there. This product has helped to drastically improve the quality of my smokes!
I keep one of these in a travel 18 cigar humidor, and my cigars have almost always been fresh. If you are in a very humid place to begin with, beware, i got musty cigars once when i spent some time in MPLS in the summer months. But in an arid climate, like Colorado, these are the perfect solution!
These Drymistat humdifier tubes are AWESOME! Another example of better living through chemistry!! !Put them in your humidor and you're done...humidity is perfectly regulated at 70%. Their shape also makes them perfect for my travel humidor or 3 finger cigar case. I initially bought one to try out but recently purchased 2 more. Highly recommended!
Not the first time I have bought one of these. I use one in my travel humidor and a few in my 25-50 capacity humidor, more or less depneding on how many cigars and season. Maintains proper humidity if maintained properly as described by the manufacturer. Refill with distilled water to indicator markers, shake, let sit 5 mins and return to humidor with no spills.
Answer: i can tell you that it is a plastic tube filled with some kind of absorbant globules of gel. the top fits securely in the tube. the plastic is like a plastic soft drink bottle. it could definitely be squashed with a small amount of pressure. but if you had it in a travel humidor, i dont think it would leak...it holds maybe a couple of table spoons of water...and it works well. keeps my small humidor at exactly 70% humidity.