What is this first stage?

[jborg]

I was looking at a local deal for a set of doubles regulators, G250v with ... something. I didn't recognise the first stages and it wasn't specified so I asked and got an answer and pictures: "Mk25s, best ever":

That doesn't look like what I recognise as a Mk25 (I have a couple of those, of different vintages). Or, I mean, it does in general body layout, but no balancing chamber holes, just indentations? Is it just an unusual, older model I'm not familiar with?

 

[jborg]

Oh, I guess it's probably some sort of Mk19... But, without a hat and with holes at the top that I don't see on a Mk19 picture? No, I'm still confused.

 

[Tanks A Lot]

This looks to be a ScubaPro MK18 with the soft cap missing. I do not see the fins that a MK19 would have on the diaphragm retainer.

 

[lexvil]

This looks to be a ScubaPro MK18 with the soft cap missing. I do not see the fins that a MK19 would have on the diaphragm retainer.

Interesting that some many questions about the mk18 lately. That is my guess too, MK 18.

added; the ambient holes are at the top in the picture.