Jaeger-LeCoultre

This is a picture of a Geophysic 1958 with the caseback off. Do you see that black perforated ring between the movement and the case? What is it? I'd think "it's just a spacer ring filling the difference in size between the movement and case" but I've never seen one that looks like that before. Might it be some kind of extra shock absorption? Any ideas or (better) knowledge?

Trying to limit heat transfer into/out of the case?  Certainly not part of WR with those perforations (!)

I suppose that would imply that it's a material that's a worse conductor of heat than gold or steel is.

Normally questions are questions.
Nothing special.

But… questions about watches, yes, that is a different story.
To the point, what is that ring into the watch of blau?
It looks not that bad.
So i think JLC did it to make the Geophysic 1958 more a tool watch.
More stiff, better closure, because it is a traveller. Geo, geologic, travel.

the circular holes would seem to fit with that function

Clemens think also that it is a kind of shock absorber.

In mind JLC do not put something in a watch that have no function, so we sit in the good direction.

Clemens wrote about the Certina DS, and to ad another specific watch outside a Casio G Shock, IWC have a special Big Pilot with a very ingenious anti shock system.
They hang the movement into the watch case.
For the model name, India Whisky Charly our moderator know more.

That was something Certina pioneered in the 50s with their DS System, their watches could withstand falls from a few metrrs of height so I guess it really works and is more than just a gimmick...

My thought had been rubber, something that can eat up the shock by deforming, but then return to its original shape.

Nice way to put a ring into a watch (I'm ironic).

that this is the anti-magnetic cage made of soft iron (like read in reviews of 2014/15 - Monochrome, Hodinkee et al.). Like the Original the Tribute 1958 supposed to be a magnetism-proof watch.

It is not a shock absorber, but a technical and patented solution to allow the screw in case back  engravings to be perfectly aligned when the case back is removed, then screwed again. 

I'm curious why JLC can be this precise in screwing on a case back so accurately, but the general consensus is that watch brands cannot effectively manufacture screw slots that align. In that case, JLC should license the technology to the entire industry. This patent also sounds more like a piece of tooling than something that needs to be included within the watch as assembled in a plastic form. There doesn't appear to be anything in the watch back or inner casing that is used to align with the plastic ring. This also doesn't appear to be true from a Google image search. I may have Googled the wrong reference, though!

Was there a technical reason why JLC skimped on gold rotor weight?

But was this not in era when this exact rotor design had gold weight, there is even the cutout at bottom where 22C is stamped on other MC steel models? I understand situation now is different.

A Faraday cage or Faraday shield is an enclosure used to block some electromagnetic fields.  Usually made of iron to direct magnetic or electric fields around the object it is protecting.

Its the faraday cage.

Every JLC tribute to Geophysics case back I saw were never aligned. Who was the inventor? I curious and want to look into it further.