An accessory used to fill open, nonwired cavities in a connector grommet to prevent the entry of moisture or fluids or foreign particulate contaminants into the connector.

A plug which is inserted to fill an unoccupied contact aperture in a termination assembly. Its function is to seal all unoccupied apertures in the assembly, especially in environmental connectors or junctions.

a safer alternative, of course, although I could not follow this technique even if I had wished to do so, since the plug was missing from the review sample