NOT Evil Grommet
This new grommet replaces the older style black grommet, also known as the 'Evil Grommet', which was prone to slipping through the hole and contaminating the fermentor. This new grommet is designed to prevent this problem and ensure a secure and sanitary seal. It is designed to fit a standard size airlock. The diameter is the same as the hole in a standard rubber stopper or grommeted lid.
