Reliable material: these airlocks are made of pp plastic, which is odorless and non-, the airlock grommets are made of silicone, and soft, safe for your use, can for a long time use Keep good seal: 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 Convenient to clean: easy to clean with practical design, the airlock can be disassembled, just use a small brush to clean completely, it can soak in bleach water to disinfect Main function: the airlock kit as versatile fermenting equipment, for a variety of purposes, such as preserve foods, ferment of cabbage, , sauerkraut, grape juice and so on, or making beer, wine, mead Specifications: Material: plastic, rubber Colors: White, Black Package includes: 20 * Silicone grommets 6 * Plastic airlocks Only the above package content, other products are not included. Note: Light 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.