180 Days Warranty. Contact seller directly if any issues, YXCC Service Team will respond you within 24 hours during working days. About Airlock Set for Fermentation: 1. Easy to use, just drill a suitable hold on your fermenter lid (follow the size of air valve), then use the black grommet insert into the lid hole, place the tapered tip of the airlock into the grommet hole to make a good seal. 2. The airlock kit serve as versatile fermenting equipment, for a variety of purposes, such as preserve foods, ferment of cabbage, pickles, sauerkraut, grape juice and so on, or making beer, wine, mead. 3. Easy to clean with practical design, the airlock can be disassembled, just use a small brush to make it clean completely, it can soak in bleach water to disinfect. HOW TO USE: 1. Remove the cap, then full the half of the air lock with the water or vodka 2. Put the cap back on and insert the tip of the airlock with silicone grommet into the lid. Make sure it seals up the bottle tightly. 3. Gasses are released during the fermentation process.you will see bubbles forming and escaping through the water in the airlock 4. Airlocks prevent oxygen from entering the ferments. Oxygen will ruin the fermentation process 5. Sometimes, remove the airlock to ""burp"" the ferment, check on your progress and release pressure (this step may not be required depending on your project) Specification: Airlock material: plastic Grommets material: food grade silicone Airlock Size:12cm/ 4.72? x 3.8cm/1.49? Grommet diameter:Outer diameter approx 1.8cm/0.7?, inner diameter 1cm/0.39? Package Includes: 8 x Plastic airlocks 30 x Silicone grommets