looks like an excellent trip saver/sanity glance solution! Perhaps you've fixed the Achilles heel of the vision, guys well done! and oh if only I had one of those adapters and a pursuits a year ago...I just might not be boring everyone with my new found love affair with manual rebreathers
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as for the price, assuming it's reliable, it's peanuts compared to what it could save you on a trip if you "loose your vision"...
Now if you could just add that mass flow orifice in a pinch...how cool would that be!