Crankcase vent hose

[Guido]

Hey guys, can anybody tell me what the solid piece half way along the crankcase vent hose is for. It has quite a restriction to it when you look down the hose.

(Ps. ZD 30 engine)

Cheers
Guido

 

[Rumpig]

one way valve?

 

[tweak'e]

its a restrictor. probably to smooth the flow.