V2  22mm One Way Flow Restriction Valve for Multiple Patient Lung Ventilation
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V2 - 22mm One Way Flow Restriction Valve for Multiple Patient Lung Ventilation

With these designs Im assuming the ventilation flow with the valves in place is sufficient and not too restricted models ...

similar models —

V2 - 22mm One Way Flow Restriction Valve for Multiple Patient Lung Ventilation alternatives
Oneway Valve
gringer