halocline
Contributor
You could try the G500 air barrel; it's a good sign that the part numbers match up. On the G500 diagram that I have that is the correct part you're referring to. I just don't know if its a plastic part as well. If it works, you might start a trend. DA would almost certainly know if it would work. I mentioned chrome plated brass because that's what SP uses in the metal air barrels on my regs.
The D series is an oddball for service, but the balanced adjustable uses the G250 kit which is very common so you would not have the same service issues. But, you already have the S600 and many divers swear by them, and it is the top-of-the-line.
The D series is an oddball for service, but the balanced adjustable uses the G250 kit which is very common so you would not have the same service issues. But, you already have the S600 and many divers swear by them, and it is the top-of-the-line.