What are these?

They are a triple or twin bubble airlock and a cylinder airlock.  Airlocks are important for all home wine and beer makers.  Affixed to the top of a closed fermenter by inserting in a bored bung and filled half way with water, they allow the escape of carbon dioxide gas produced by fermentation.  The gas bubbles up through the water.  The water prevents any outside air from entering the fermenter.  This helps to prevent possible contamination from airborne microbes.  The covers are not airtight and while allowing carbon dioxide to escape, they keep out fruit flies and other small creatures.  Watching bubbling airlocks becomes a serious pastime of home brewers and vintners.  The cylinder airlocks are not as much fun to watch as the bubble airlocks.  Some of the “bubble” airlocks have smooth rather than bubbled sides.

NOTE:  Check your water level in the airlock frequently.  They can go dry.  Some winemakers use colored water to help visibility.  Some use a metabisulfite solution for airlocks.