Copies of a single metal tile are woven together to form a cube with a concave vertex.
Any form based on connected cubes can be created with this tile.
Assembly is a matter of bending the tabs just enough to they curve into the next tile’s slot. The ones on the corners are more difficult, but putting everything together took less than an hour (the way I remember it).
Three rectangular solids make up the base. Brass pins hold the three pieces together without glue.