Those look like the same thing the Post Office provided... and I still don't know why, but I wish I could find it again.
I find myself using the magnifier on my smart phone at times to read some small label or something if my cheaters aren’t handy.
So far, I have been unable to start a fire with it.
LOL. Very asstoot sensa yuma.
I remember some guy claiming he could start a fire with the reflection from the concave bottom of some food or drink can. Boy, that had to be one highly polished and perfectly curved food can, besides being big enough to capture enough solar energy to concentrate the rays to an ignition point. And he had to live on the equator.
I didn't call him on it because I've seen enough "impossible" things over the years, but my Doubting Thomas instincts sure came to the fore. I too, without visual and manual demonstration, will not believe it.