SMART DATE-TRACKING FERMENTATION LIDS: Mfacoy's innovative silicone pickle caps feature an easy-to-set date tracker, so you can monitor fermentation time at a glance-no guessing or forgotten batches! Perfect for sauerkraut, , , and more. AUTOMATIC GAS RELEASE, NO BURPING NEEDED: Our patented one-way valve design vents excess CO2 effortlessly during fermentation, eliminating manual burping or messy water airlocks. Just seal and let the lid work its magic! PREMIUM FOOD-GRADE SILICONE: Made from 100% silicone, Mfacoy lids are , dishwasher-safe, and 't crack or warp. Safe for fermenting veggies like cucumbers, carrots, and garlic. FOR WIDE-MOUTH JARS: Designed specifically for standard wide-mouth jars, these low-profile lids seal tightly and spoilage while saving space in cabinets or drawers. FOOLPROOF FERMENTATION EVERY TIME: Avoid exploded jars or failed ferments! Mfacoy's airtight silicone seal and auto-venting valve keep oxygen out and pressure balanced for -rich, perfectly fermented foods. Color: Mixed Color Material: Silicone Package Contents: 4*Fermentation Lids Only 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.