My home was built in the late 50s so there are a few things that no longer work or that need a little help to work. One of those are the foundation vents. I have a total of 6 and only 2 of those mechanisms actually close for winter so I had to come up with either a replacement or a variation. This choice works perfectly for the vents on my home.
Simply make sure there’s no obstructions or debris on your vent before placing the vent cover. Then set it in place and press the spring lever in and turn it until it latches onto the vent. When it’s time to remove them, simply press and turn again until it unlatches. It’s that easy!