Roof vent fitting

I need to replace one of the roof vents on my Duetto. They are the type with two operating handles.

The instructions supplied with the new vent state that they should be installed with the handles facing the front and rear of the vehicle. Mine are currently installed with the handles facing the sides.

Have they been replaced at some point and fitted incorrectly or is this how they should be?
Ta....

We have a 1996 Duetto. Our (original, I assume) roof vents have the handles on the sides.

Great van, by the way.

Thanks for the response. I decided to stick with the way that mine (and yours) was fitted.