Summary

15-strand 360 degree Mini tree topper designed for pixel-strips.
Designed for a 1/2" EMT.

Place a bolt/screw through the topper so that the topper sits on top of the EMT, then a smaller section of EMT can be placed in the top to attach a star

The tree in the photo uses 300 pixels (20x15). The star is a print of https://www.thingiverse.com/thing:4589156

Bottom-hoop is a 16" wreath frame from Hobby-Lobby