jansamn 12 pcs airlock grommet, fermenter lid grommet,silicone grommets for mason jars/airlock/straws/plastic bucket fermenter lids,5/8" od & 3/8" id (fermenter grommet) jansamn features: ★ any airlock fit into the grommet ★ made of super durable and long lasting silicone ★ the silicone grommets will fit both metal and plastic lids ★ these fermenter grommets made it easy to make an air tight hole for an air lock ★ use the airlock grommet to turn mason jars into drinking bottles ★ used these grommets to make my own airlock lids for fermenting ★ best to start with smaller hole and work up to the 1/2 inch hole to insert the airlock grommet package including: 12* silicone grommets