• BRASS SCUPPER PLUG Expanding Water Plug Head

A scupper is an opening in the side walls of an open-air structure, for purposes of draining water. They are usually placed at or near ground level, and allow rain or liquids to flow off the side of the open-air structure, instead of pooling within the walls.

Ship's bulwark and scupper in Russian and English
 

There are two main kinds of scupper:

• Ships have scuppers at deck level, to allow for ocean or rainwater drain off.
• Buildings with railed rooftops can construct scuppers to let rainwater drain off, instead of pooling within the railing of the roof. Scuppers can also be placed in a parapet, for the same purpose.
• Traditionally, plumbers also use this as a water plug.