Lid Material:food grade Polypropylene Lid diameter:86mm Fit for all Wide Mouth Mason Jar The second generation Lid comes with two self healing injection for injecting culture to inoculate the substrate more average and a PTFE syringe filter for avoid contamination without glue,more healthy for mushroom growing. These lids can be used in a microwave, autoclave or pressure cooker. Our professional grade autoclavable wide mouth jar lids are built to be lab-quality, and made specifically for liquid culturing . Leave the lids a quarter turn loose while in the pressure cooker so air can escape, otherwise the injection ports will pop out.