Perfectly designed for mason jars, this one-way airlock lid secures firmly with a durable stainless steel ring. It allows carbon dioxide to escape while preventing oxygen from entering, creating the perfect environment for fermentation, especially for quick ferments like vegetable mixes.This set includes a stainless steel band that resists rust, ensuring long-lasting performance.Features:8.2cm diameterStainless steel bandPlease Note:This comes with one silicone seal in assorted colours that we cannot order specifically. If you require a certain colour, please let us know and we will try our best to meet your needs. If you order multiples of one colour it may not be possible to fulfil your entire requirements.