Rashi: They are like caps. Gra - Each Koseres was like a ball. The top half was like a cap.

Malbim: It is like a copper net.

Rashi: They were surrounded with the forms of date branches - "v'Al Sevachah Yis'halech" (Iyov 18:8). They had windings, like chains.

Gra: They are chains from which the pomegranates (verse 18) hung.

Rashi: There were the forms of seven date branches for one circumference, for one cap.

Gra: There were seven layers of half-spheres, one on top of another.

Malbim: [Under the copper net were] seven chains on each crown.