Anyone know what these are….?

[Ronin0033]

These were in a bulk load of bits I picked up, but I’m not sure exactly what they are….

I’m guessing a green gas converter for CO2, but for what? They have a green gas inlet in the bottom, and would fit a co2 mag slot, but the threads are very corse. 
 

I may just save the valves from the bottom if they remain unidentified. 
 

Cheers! 

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