OK, now I know when I’ve seen that BORUiT.
Fitorch P30Z looks very similar:
They even seem to use the same lens.
A lot of these look like pretty simple TIR lenses, like what's on my olight s1
Yes, these are pretty simple but not as simple. A zooming TIR has a convex lens at the front (sometimes plano-convex and sometimes biconvex). On the outside the design is different as well, the front lens-air boundary is usually not flat but sloped with the outside part facing forward. Frankly I don’t know why but that’s how they do them.
Overall - there’s nothing special about such lenses but they just don’t tend to be the standard (yet?).
Today I found another few TIR zoomies:
2*18650 variant of “P7.2”:
Headlamp?
And 2 PopLites:
