Whats the benefits of a Fan-tastic vent

A fantastic fan in a roof vent will help keep your rig cooler. Turn the fan on and open a window at the opposite end of your rig. The fan will pull a tremendous amount of air through the rig. They are exactly what the name says FANTASTIC. Great customer service, too. The biggest benefit I like is that you can put a cover on the roof over the vent so it can stay open during the rain.
I have 2 and would not want to be without them.

We have two of them, really a nice addition. I can't speak for all the models,but ours;

Remote control, you can open, close, adjust speed, and/or reverse the flow. Really nice at night to blow cool are into the bedroom.

Set it to open and start at a pre-set temperature in the RV.

Closes automatically if it starts to rain.

Moves a LOT of air, set one to blow in, the other to blow out.

One drawback is that it will pull sever gas smell into the RV if you don't have a window(s) open OR one fan to blow air in, while the other exhausts air out.

I bought my trailer used and wished the owner got the option for the 2nd fantastic fan.

We had one install in our bathroom. the original was too high to reach the on off button. Dealer offered me the fantastic fan, so we put it in. It came with a remote, and you can get any speed you want. It quickly removes the moisture from a shower, and of course odors. We usually run it on slow. Very quite. It's a very nice fan.

Have 2 also with covers.
Place them in auto..select speed....set t-stat...select In or Out
One pulls air IN the other pushes air Out.........lots of air movement

Run them in manual.
Run them when its raining
Run them both Out with a window or two open
Run them both IN with a window of two open

AIR MOVEMENT...........that's what it is all about.

AND the company has been fantastic to deal with........even when 'warranty' has expired they still will respond usually with free parts

They also stop the smoke alarm from going off when the wife is cooking.
Seriously, they move a lot of air especially handy when you can't run the AC.

We have 2 and one is set for intake at the shady end of the rig and the other for outtake on the other end. They really do a good job of removing stale air and circulating fresh air throughout the interior. They also have sensors that will automatically shut them down if they detect rain.

Thanks for the information, it sounds like the salesman wasn't all smoke and mirrors after all.

Love mine so much that instead of an AC in the bedroom, I'm going to install a second one.

Moves a lot of air and is perty quite