The vent is the "hole" where they defecate out of.
vent hole ,ventiduct
it is a vent
The top two holes are a fill level, and a vent hole. Remove both of these plugs when filling the gearcase to ensure proper oil level, and ease of filling.
Vent
It's a vent.
It's a vent.
Tobbing foundry, production foundry, captive foundry, independent foundry...
The hole in the shell is generally termed the air vent.
a transformable hole in the eaerths surfsce
spiraculum
It's a vent.