-PERFECT FERMENTING LID: Transform your jar so you can ferment all types of vegetables! This mason jar accessory has an adjustable platform to keep the produce submerged and has an air tight seal with a one way release valve for easy fermentation -FITS WIDE MOUTH: Compatible with wide mouth Ball, Kerr, Anchor, and Kilner canning jars! -ADJUSTABLE PLATFORM: Not only does this mason jar canning lid come with a CO2 one way release valve but it also comes with an adjustable platform -EASY ASSEMBLY TIP: Place mason jar implement on top of the jar so that it rests on the rim of jar; Screw down band over implement onto jar, if you have difficulty assembling, run the silicone band over hot water for 30-60 seconds -MEASUREMENTS AND CARE: Nylon Mason Jar Fermenting Lid is made for wide mouth mason jars and measures: 3.25” x 3.25” x 2”. Hand wash only, not dishwasher safe. Jar is not includedPackage Type: Peggable color box-not plastic