Wiktionary
end caps
n. (plural of end cap English)
Usage examples of "end caps".
Had Verna lit all of the reflector lamps lining the walls and hung on the end caps of shelves, the place could have been made to be considerably brighter but, for their purpose, she didn't think it necessary.
A buckytube is simply a buckyball with a long, winding spiral of hexagons between two half-buckyball end caps.