We designed the sleeve to fit tight enough that it won't fall off, but loose enough that it is still easy to get on and off. Kerr is the only currently available wide mouth half pint jar, so the sleeves are designed to fit them.
Use a different color for each family member, and stop wondering which jar is yours!
This size does not have a hole in the bottom, so you can also use it without a glass jar inside.
Microwave safe means you can heat up your food or beverage without removing the sleeve.
Since they don't touch your beverage, I often just rinse them, but they are also dishwasher safe. You can leave them on the jar, but I find that water gets trapped so I prefer to separate them to clean the jar.
You could also use one to block sunlight or prying eyes from the contents of your jar.
Great for kids and adults!
