Only the 24oz size is coated with polyurethane, which is a plastic. This helps them go on and off the jars easier.

When I need a little extra coffee, I go for a pint & half jar. My silicone sleeve keeps my hands safe, and if I need to leave the house I screw on a wide mouth silicone drinking lid.

Use a different color for each family member, and stop wondering which beverage cup is yours!

Microwave safe means you can heat up your beverage without removing the sleeve. Or take out a frozen jar of food, put a koozie on it, and heat it up.

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!