This is intended to join equal sections of 3/4 inch PVC pipe into an icosahedron. To make an entire icosahedron, you'll need 12 of these, which altogether will require about a kg of filament, depending on your slicer settings. You'll also need 30 equal lengths of pipe. So-called "1/2-inch" pipe requires scaling by 80%.
The picture was a rendering from Blender software.
Two versions are available: The original design, perhaps nicer looking, and a newer one that should be more printable.