Type of acrylic crystal used foe ZEX?

M&W,
Hello to everybody here and I have a question if somebody could please enlighten me as to the answer.

As many will likely remember as it was somewhat of a icon then and still, there was the first ref. ZN-001 Zeno-Watch Basel (i.e. Japanese Miyota c.8200 series mov't) "Explorer" [ZEX] from the early 2000s (which Eddie sold at TF for a now amazing 80 GBP when he was an AD for Zeno). There was also the subsequent Swiss made ref. 1249G ZEX with the ETA c.2824 mov't, as well as the latest and still current (AFAIK) Swiss made ref. 6704 ZEX with the vintage NOS A.Schild c.5206 mov't.

If anybody has ever changed the original factory acrylic crystal on any one of these three above versions of the ZEX, could you please tell me exactly what type of domed acrylic crystal Zeno actually used for these?

In other words, did Zeno use the British MoD domed and "armoured" type acrylic crystal design that is secured into its seat in the maincase by a steel tension-ring inside the rim of the crystal?

Or did Zeno possibly even use the homaged Rolex ref.1016 Explorer's own original plexiglass era OysterCase crystal design in which the separate bezel tightly clamps the cupped plexi/acrylic crystal onto an integral steel lip circumferentially machined at the mouth of the maincase?

Or did Zeno perhaps just use a modern method of manufacture "pieced and pressed together" type economy case wherein the domed acrylic crystal is simply glued into the bezel and the bezel/crystal unit is pressed into the main or lower half of the casing, etc., etc.,?

Any information anybody might have on this would be greatly appreciated. Thanks