Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:506634.

This design is part of the Platonic Solids. This version is hollow. I use it a test bed for 3D printer quality (and slicer software). It prints quickly. Has also been used as giveaway prints at exhibitions.

(The green picture shows quality differeneces in 2012. The rightmost is from Shapeways.com, the leftmost from a very early RepRap)