This part replaces a Zome ball where you need to have two yellow lines intersecting, lying in the green plane. Its purpose is aesthetic, when you don't want to use a ball to make the junction. This might happen if you're trying to represent a mathematical object wherein balls should represent vertices, not false vertices arising from edge intersections.
Twelve copies are modeled as a single print, with small sprues connecting the individual bobs. They can be twisted apart, then cleaned up with a sharp knife or nail clippers.