These wide mouth mason jars have a unique design that allows them to securely nest and stack with each other when not in use, saving 30 percent more space versus Ball Regular Mouth Pint Jars. Compatible with other Ball wide mouth jars, these 16-oz., BPA-free Nesting Jars are not only canning-safe and can seal for up to 18 months, but they’re also ideal for drinkware. They’re even shaped to fit perfectly in a cup holder for on-the-go drinkware use.