Originally Posted by clubhouse
I use MaxxAir II. Love them. Chose the II over originals because the II can hinge open after installation if you need to get to the vent for cleaning.
I think function is more important than brand, how ever MaxxAir are proven and with a few minutes web search they can be had about as low in cost as any.
Installation is DIY and took ~15-20 min per vent.
X2. I put a Maxxair II over my bathroom vent last week. ... works great. I left the went open after installation. It's rained twice since then with no water getting inside.
They attach to the vent frame, so your roof is not involved. All you do is drill 4 holes and use the supplied hardware. One suggestion: attach the brackets first and place it in position over the vent to see the final position. After installation, the brackets will hold the cover off the roof.