A torus made from pieces that are the union of cubes. 5 pairs are needed to build the torus.
Piece pair to print View STL
Also hosted at Thingiverse
Print five pairs to construct the torus. Overlay mirror image pieces and then insert the final cube to lock into place. The pattern will wrap around into a torus. I needed to use needle nose pliers to squeeze the final locking cubes into place.
Constructed using the puzzlecad library for openscad. Current version at: https://github.com/aaron-siegel/puzzlecad