Tech diving regulator?

[LCoolio]

If you are diving where your reg freezing is a serious threat I’d suggest that you prioritize having regs that don’t freeze. Maybe not for class, but after that.

The US Navy has done extensive testing and has approved three for cold water. Look for cold water regulators on:

https://www.navsea.navy.mil/Portals/103/Documents/SUPSALV/Diving/12-07-2021.pdf

One is from Poseidon, one from Mares and the last (newest) from Interspiro.
Look at the notes, the part numbers matter.

There are other lists from organizations that do cold water diving that you could use, but if nobody who dives professionally in cold water uses a reg you probably don’t want to either.

The Canadian Navy uses the interspiro divator mated to a Apeks DST 1st stage, including for ice diving. Seems to work pretty well

 

[rhwestfall]

Ice? I'm partial to my Double Hose...

 

[PietroT]

I am talking about the plastic transparent diagram on the end of the regulator. If this punctured it still works under water? What is this for?

It still works, but in very cold water it might freeze. As others have already written, that is the environmental cap.
I use DS4 on my bailout tank. I see extremely difficult to have the environmental cap punctured.