John Gill Commentary 1 Kings 7:16

"And he made two capitals of molten brass, to set upon the tops of the pillars: the height of the one capital was five cubits, and the height of the other capital was five cubits." — 1 Kings 7:16 (ASV)

And he made two chapiters of molten brass, to set upon the
tops of the pillars
These were large ovals in the form of a crown, as the word signifies; or like two crowns joined together, as Ben Gersom; or bowls, as they are called, (1 Kings 7:41) ,

the height of the one chapiter was five cubits, and the height of the
other chapiter was five cubits ;
in (2 Kings 25:17) they are said to be but three cubits high; but that is to be understood only of the ornamented part of them, the wreathen work and pomegranates on them, as there expressed; here it includes, with that, the part below unornamented.