Wall plug has hollow glass washers filled with sealant mounted between its upper section and threaded lower section which are fractured as plug is screwed in and seal bore

摘要

The wall plug has hollow glass washers (6) filled with sealant which are mounted between its upper section (3) and the threaded lower section (2). These are fractured as the plug is screwed in and seal the bore and any cracks that may have formed around it.