These lids are used to seal jars. Their inner rubber seal prevents contaminants from entering the jar once the heat is applied to the jar (while the lid is on). This heating process is usually done via a pressure cooker.
Many mycological hobbyists make adjusts to these lids to incorporate self-healing injection ports and micron filter patches.
- Fits all regular Mouth Jars
- Can Be Reused 2-3 Times
- Perfect For Mushroom Cultivation