Reliable material: These airlocks are made of PP plastic, which is odorless and non-toxic. The airlock grommets are made of silicone, durable and soft, safe for your use, and suitable for long-term use. Keep good seal: Easy to use; just drill a suitable hole in your fermenter lid (according to the air valve size), then insert the black grommet into the lid hole and place the tapered tip of the airlock into the grommet to create a secure seal. Convenient to clean: Designed for easy cleaning, the airlock can be disassembled. Use a small brush to clean thoroughly, and it can be soaked in bleach water for disinfection. Main function: This airlock kit is versatile fermenting equipment suitable for various purposes such as food preservation, fermenting cabbage, sauerkraut, grape juice, and making beer, wine, mead, and more. Specifications: Material: Plastic, rubber Colors: White, Black Package includes: 20 x Silicone grommets 6 x Plastic airlocks Note: Light and different displays may cause the color of the item in the picture to vary slightly from the real thing. Measurement allowance is +/- 1-3 cm.