Psvane Teflon capacitors real or fakes?

These are great looking capacitors and supposed to be competing against the Audience, Rel, V-Cap, and Sonicap Teflon capacitors. A couple of my tweaky friends who have no end to new capacitors gave them a try and had one quit after a month or so, and with the wire cut off, no return possible. So they cut it open, yes they are curious, and according to them, the guts looked like mylar, measured like mylar??? Could these not be Teflon caps after all??? I open this for discussion with some of the tweaky electonic minds out there to get to the bottom of this. If they are not genuine teflon, I would not want fellow audiophiles to get ripped by another false claim. But to be fair, real verifiable data should be submitted here, no guesswork. I trust my friends, but I did not do the test, so I open it to other philes. Hey, I like a great deal too, but if it is not as advertised, I get pissed too. Take a look fellow philes, and lets solve the mystery....Jallen