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There are a lot of valves on an Inspo/Evo ... solenoid valve, drysuit style manual gas addition valves, 2nd stage valves, 1st stage valves, gas dump valves in counterlungs and BC ... you get the idea, Bill. What are we talking about when it's named rebreather valve?
My guess would have been some form of gas addition valve for the loop, adjustable cmf like the Azimuth or Submatix, cmf with manual bypass for O2 like Jetsam or Hydrogom, or solenoid valves. They're the ones pretty much unique to rebreathers I guess.