Installing a vent cover on the roof of your rig is a snap. As you can see from the first photo, the instructions are attached inside the vent cover with tape. The little packet at the bottom of the instructions includes all the parts needed to attach the vent cover to the vent.
It requires drilling four holes on the vent shroud but that is the most difficult part. Well, maybe getting up on the roof with your drill and a couple of other tools is more challenging. It helps if you have someone inside who can raise and lower the vent for you as you work. You need it up when you put the screws nuts and washers in place, but you need it down again when you fit the cover in place.
You can see where I attached the brackets that hold the cover to the vent in this photo. This requires drilling a 3/16" hole at each location and inserting a stainless steel screw with a washer and nut also stainless. The metal is soft and the drilling is very easy. You need a pencil to make the hole locations.
Camping World had this model cover on sale for eighteen dollars while the MaxAir II models cost twenty nine dollars apiece. I have one of these on another vent and can see no real difference in quality. The older Maxair II cover on my rig is very brittle now and is beginning to crack and break. I will likely need to replace it one of these days. It is about six years old and was on our previous rig.
This photo shows the new vent cover in place and the tools and instructions required to do the job. I think the whole project took me about 30 minutes to complete. The model installed is called a "Rambler" vent cover. You can see a portion of the MaxAir II cover on another vent just to the left of the new one.
I had an older MaxAir in this location too but it fell apart when I removed it to do annual cleaning about a year ago.
I recommend placing vent covers over your vents if you can. They allow you to keep the vents open during rainy weather which helps in preventing you windows from fogging.