#10 corks are all natural corks from Spain. They last indefinitely with the right care. Simply store them outside of your container when not in use so that they can dry out. Cork is mold and mildew resistant. They only need to dry out when your container is empty. Air space, darkness, and moisture can over time discolor the cork.
Use the #10 cork for the 4" long body cooler. The opening of this tube is just a bit narrower than the 3.5" tube. The #11 cork will go into the 4" tube but will sit high enough that you may lose the cork if you have a sculpture on top.
The #10 cork works well on most wine bottles. It is a standard wine bottle sized cork and is perfect for a tight seal when you want to save your wine for a later date.
Any container that has a standard wine bottle size opening will work well with this cork. Syrup bottles, flasks, and other fluid holding containers work well with natural cork.