These are Wide Mouth Mason Jar Lids w/ Rubber Stopper Self Healing Injection Port + Gas Exchange Port. Just fill with your grain spawn medium, cover your lids with aluninum foil, and place in your Pressue Cooker for an Hour and a Half! Let Cool then INject with your favorite species of Mushroom Culture.
 
6 LIDS FOR 25.00$
12 LIDS FOR $35.00