I had been making small tritium fobs for decades, since the early 2000s. Had an overseas supplier of naked tubes, mostly about Spark sized. I would drill out acrylic rod, fill with silicone via plastic syringe, insert the tube, let cure, then cap with liquid acrylic, and put it on a split ring or cord. Worked, but took a lot of time. But my flashlights, keys, etc, along with a few select friends, were some of the only people sporting tritium fobs that I knew of for a long time. Decades of finding our keys or flashlights faster than everyone else... and that peace of mind.
Very happy to finally have a licensed US manufacturer, making quality complete tritium fobs, at a reasonable price. So much less work than sourcing vials and making them myself, and super high quality and consistency.
The Embers are very bright, 360 unimpeded illumination, compact, and sturdy. The "glass breaker" I don't think would do anything, but likely an easy way to heat set seal the vial using a metal plug. And maybe they had a mandate to make it show up in an xray?
I have traveled with these extensively overseas and in the US, and never had any problems. Pretty sure security understands they're totally harmless.
My home made vial housings were smaller diameter than the Spark, so could use smaller tiny 0.25" split rings. Would be a nice upgrade to shrink the Spark. But even the larger Ember, is still small, and the Ember is substantially brighter than the smaller vials I am used to. Really a nice upgrade, and makes a great gift. (carry one or two extra on the key chain, just in case you want to upgrade someone)
If the 1/2" split ring is a bit too large for your pocket flashlight setup or whatever, you can always remove the split ring, and hang the fob directly from cord. The mounting hole is a bit over 1/8", so fits large range of cord sizes.
Love to see some of Rhino's flat tritium patches available as glue-ins or stickers. For now, the Ember is my goto for my gear, and for gifts for friends. Keep your friends well equipped and ready to face anything, makes it more likely they could be there when you might need it.