What is it?

[Stephie]

Mares 2nd stage - but I have no clue beyond that.

 

[Fishpie]

Welcome.
If it has the bypass tube (can't see from pic) it could a Navy.
No tube and it's the Beta or most likely what they called the Beta before calling it the Beta.
......quite a good reg (like all Mares are) but the plastic tabs that hold the valve body straight on the inside of the case have a tendency to break, allowing the demand lever to turn and not be aligned properly with the diaphragm.

.....don't forget to remove the little orange clip before trying to open.

 

[Stephie]

Thank you. I was lost.
I haven't gotten it yet or I would take other pictures. Just bought it on eBay.
I'll be truly surprised if it's functional.
I'm collecting the solid retro brights for an art project and will be happy even if it's junk.
I just want to know what they are before I start filling hoses with wall foam and attaching neoprene flower petals.