These metal lug finish lids are a direct replacement to the lids included with the FE319 1 Gallon Glass Jar Fermenter Kit. After prolonged use, the metal lid may show signs of rust similar to mason jar lids. This is the only part of the fermenter kit that may need replacing from time to time. You can reuse the original airlock grommet, but if you need a new one see below under You Might Also Need.