Older Scubapro regulator ID

[ams511]

Early 108 had a fixed, non-adjustable orifice. Newer models have the same adjustable orifice as is found in most modern SP 2nds. I believe you can tell by the thickness of the "nut" on the demand valve housing (screws into the case). The thin nut is about 1/4 inch thick and has the fixed orifice. The thick nut is almost 1/2 inch thick (I can't find one right now) and takes the adjustable orifice. With the fixed orifice, you could tweak the cracking pressure by adjusting IP a bit after lever height was right.

From what I remember a non-adjustable 108 also had a different exhaust valve and tee.

 

[boat sju]

Thanks Couv, now I've got it. I think I must have a 108 and an 080 HP.