Sharing similarities to Mason jars, our Economy Round glass jars feature a wide mouth opening and have what seems like a never-ending list of uses. From pickled vegetables, canning and preserves, to sauces, candles and more. Available in sizes of 12oz to 1 Gallon, the Economy Round jars provide a consistent package for all your needs. Economy Round glass jars, often referred to as "Mayo Jars" also come in both "C/T" (Continuous thread) and "T/O" (Twist-Off) finish in certain sizes. Their round shape makes labeling these jars a thing of ease.