Go here and you can find anything you want to know about scubapro regulators
First Stage
I like the site, but I have to say some of the time lines and pictures seem to be skewed to fit their collection rather than actual history.
For exmaple the "D400 Demo" - the picture and title implies that cover was some sort of oddity when it was the cover found on all late production D400's. And there is no reference tot he change in cases in the middle of D350 production - early ones used D300 cases and later ones used the same case that was continued with the D400, meaning all D350's are not the same and parts are not all interchangeable.
Or, the 85-89 Balanced Adjustable, like all the BA's they show, has a splined rather than knurled adjustment knob. l personally never saw a splined knob until the G250 came along and then I never saw one on a BA until after SP ran out of the existing stock of knurled knobs. None of them also shows the intermediate raised lip rubber purge cover that was common on 108, 109, and 156's during the 80's - just the early round holed small lipped cover and two variations of the later oval hole style, but no retangular holed covers. There is also no reference to the final shot blasted finished Balanced Adjustables.
There is also no reference to the very early downstream 108'esque regs that were very different from the 108's pictured in terms of smaller exhaust valves, distinct non adjustabel orifice and inlet fitting design with different angles and levers, exhaust tees and the internal shape of the rubber purge covers.
As noted above the site implies you could learn "anything you want to know" when in fact the history and details have been abridged to fit the collection - a very bad way to present "history". It is similar to an approach where we would just leave out one of the US presidents just because we lost all the pictures of them.
