I have a habit of sipping seltzer water and putting it back in the refrigerator and covering it with plastic wrap. A cap works much better. The cap fits a Polar selzer water can perfectly and snaps onto the top. The only other can I've tried it on is a Kern's guava juice can and the cap is just a bit too small for that can so it may need to be adjusted for other cans.
The author marked this model as their own original creation.