The "Boy-cube", 2nd version.
Model: Anthony Phillips. Imagery by C. Tardy.
This is another polyhedral version of the Boy surface, suggested by American mathematician Anthony Phillips (inventor of the first version of sphere eversion) as soon as he became aware of the one I had proposed. It's purely a matter of aesthetics. This model differs from mine in that the "pole" of the object has been "pushed in." In a smooth version, one would then obtain what is called an "ape's bottom" (authentic).