These rubber rings are designed for use with Weck glass canning and storage jars, providing a secure airtight seal when processing foods in a boiling-water bath. Sets of 4 replacement rings for Weck jars; two sizes available. Small: 2" inside diam., 2 1/2" outside diam. Fits 35.9-oz.-cap. juice jar, 20.2-oz.-cap. cylindrical jar and 5.4-oz.-cap. mold jar. Large: 3 3/5" inside diam., 4 1/8" outside diam. Fits 12.5-oz.-cap. and 19.6-oz.-cap. mold jars. Made from natural rubber. Seal is easy to check at a glance: the pull tab on the rubber ring should face downward. Dishwasher safe. Made in Germany.