Glass jars specially designed and heat-treated for use in home canning. Ideal for fresh preserving whole fruits and vegetables like peaches and green beans. Enjoy homemade pickles year round with Kerr's famous glass jars. Kerr glass preserving jars go beyond fresh preserving to help you with serving, creative décor, and gift-giving. Lids and bands are interchangeable with Ball or Kerr mason jars. These jars are not suitable for freezing.