I just realized these things aren't threaded...I don't think I'd buy one as a result.

Not threaded, but double O-ringed. They work and there is no risk of cross threading. The only problem I've ever heard of had to do with a fairly radical pressure change which effectively hermetically sealed the matches, but that was from someone who does special and weird things for his government paycheck.

No scuba, no halo, you'll be fine. :P

You ask-Where can you place striking material? The knurled surface area,or rough grip area of the Matchcase provides the striking surface for the matches.

Covering the spiderwire with a ranger band might be more secure than electrician's tape. Less tacky too if it is sitting for a while before use.

I was considering buying on to use with REI matches. Don't those require red phosphorous striker?

I have the long one and fit:
-Micro fishing kit (one of IronRaven's from awhile back, in the amber glass vial)
-5 lifeboat matches, striker strip
-2 tinder tabs and a spark-lite
-2 micropur tablets
-needle, thread, 2 safety pins

Things wound up a bit too smooshed for my liking, and a little too hard to get out of it when needed. Then I realized I use it more as just a matchsafe than as a kit, but it's still a good alternative for a tiny kit.

A friend of mine did a deep dive with one and experience the same thing... he was curious what would happen and now has it in his office. You would swear it was welded shut.

Thanks. Still waiting on them, so I took the time yesterday to rebuild a medimum sized kit. Buggered it up, and have to redo it again tonight (if the boys let me).

Christina,
If you've got the matches, you don't need the spark-lite.
If your going to use the spark-lite then loose the matches. More tinder is better. Always assume that you need a substained flame for your tinder. Tinder is always presumed to be damp.
Personally I would go five lifeboat matches and four tinder-quick. One disadvantage of the spark-lite is that you need to have one good hand to use it. With matches you can use anything part of you that can grip. Like, oh say, your teeth, elbows, palm of your hands.
The reason why I use spyder wire is that it can be used for many things. Including sewing.

Christina - I like your fire backup - more fire makes me happier.

The Scuba situation is interesting. Shouldn't increasing exterior pressure make it impossible to open submerged, but once you return to the surface, assuming there was no gas or liquid exchange past the two o-rings, shouldn't the interior pressure again match the exterior pressure and shouldn't it operate normally? At high altitude though I might think the higher interior pressure might blow the cap, reclosing it would be a mistake because then returning to say sea level would mean you've got low pressure under higher pressure making it difficult to open.

If someone has one of these that seems welded shut, it isn't much more than a paper weight anyways, I vote they put steel pins through the top and bottom lanyard holes, secure each pin to the sides of a large vise (weld them on?) and slowly screw the vise open - see what happens. You may rip the pins through the brass or aluminum, you may pop the seal, or the whole thing may EXPLODE (probably not, but I like to disclaim). Doing this is unsafe, so if you decide to risk it wear protective gear! Have jacket, pants, gloves, and face/eye shield, ear protection as well. While I would do this, I have bad judgement, anyone reading this should not attempt such a silly and dangerous thing.