Package includes: you will receive 20 pieces of silicone grommets and 10 pieces plastic airlocks, enough quantity for your use and replacement Reliable material: these airlocks are made of pp plastic, the airlock grommets are made of silicone, durable and soft, safe for your use, can serve 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 make it clean completely, it can soak in bleach water to disinfect Main function: 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 size:Seal ring inner diameter: 8mm Material:Plastic + Silicone colour:As Shown Package Contents: 10 x Three-piece check valve 11.5cm 20 x seal ring 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.