Vent Cushion with Strap is rated 4.5 out of 5 by 2.
Insulate your roof vent opening to keep heat and light out with the handy Vent Cushion. The vent cushion has a convenient strap that makes removal from the vent opening easier and doubles as a carrying handle. Keep your RV warmer in winter by preventing heat loss. Fits all standard 14" x 14" vents. 3" thick foam with removable cover.
Rated 4 out of 5 by Cory in Calif. from Problem with thin roof I have a super lite toy hauler and the roof is thin and the vents are shallow, so the cushion pops out. With a little knife work so that the vent crank has a pocket, the cushion stays in place. We placed a piece of black out material inside the cushion for more darkening.
Rated 5 out of 5 by JRBJR from Vent Cushion with Strap These are awesome!
How does it fasten to ceiling?
The cushion fits snug into the opening and stays in place without anything to assist.