Set includes 4 air locks, 4 sturdy white screw-on lids for wide mouth mason jarsUse the sturdy, handsome storage case to improve organization in your kitchen. Makes an excellent gift for the fermentation expert in your life.Begin making tasty, healthy sauerkraut, kimchi, ginger carrots, pickles and other fermented foods with safety and easeSilicone gaskets create a tight seal between the lid and the jar, preventing oxygen and dust from contaminating your ferments.size:86mmMaterial:plasticcolour:whitePackage Contents:16 x Mason Fermentation CoverOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.