20 x rubber grommets for $38 - $1.80 each.
These grommets fit the airlocks we sell so you can attach the airlock to a plastic lid - for example if you would like to turn a plastic bucket in to a fermenter. The grommet means an airtight seal is formed around the base of the airlock.
Internal diameter 7.9mm, gauge 13.6mm, external diameter (within the "groove" 12.7mm (ie it fits a 12.7mm hole).
Not eligible for further discounts.