cooking vent

[scootertramp]

I have a 1996 PleasureWay and cannot figure out if the cooking vent can be operated from inside the van. There is no inside mechanism I can see on my van. I have a recess on the outside cover that is used to raise it open, but no mechanism to keep it open.
Is it operate only from outside, with friction the only method to keep it open ?
thanks

[themexicandoctor]

Mine is a Roadtrek & has a filter but no flap.

Its noisy, grimy, hard to clean & I woukd like modify its performance, has anyone done so successfully?