carbs

The first is an Asian USA carb. The question is, what is the function of these air/vacuum passages? Circled in red you can see that they pass through the boosters/nozzles to the exterior of the air horn. (The nozzle assembly has been removed) The second is an Asian general market carb Circled...

Anybody know what brand/type carbs these are on off 1970 f and other i believe is 1973 f1.5 look same thanks