What are these for?

[Straydog]

Sorry for possibly sounding thick.. but with the panniers I cannot work out or find out what these are for



Can anyone enlighten me please?

 

[Pukmeister]

An air entry/release valve to allow you to open a closed pannier once at altitude or when the air temp has changed.

Early panniers/boxes could be jammed shut by a change in air pressure, hence the small rubber valves.

 

[Straydog]

Thanks Pukmeister, that makes sense..