This is a grow helper for your zoanthus corals. Glue some Zoanthus to the top plug and wait. Over time the coral will grow all over the orb. After a while, you can extract the plugs and insert new blank ones.

You have to use PETG for this one and you have to use a textured plate to give the plugs some structure.

This model is designed from scratch by me. I got inspired by someone on the internet selling this under the name of ZoaBall.