Boy's Surface (Bryant-Kusner)
This surface is the Boys Surface with a parametric formula by Bryant-Kusner.
It is topoligically equivalent to the Cross-cap. See the Cross-cap page for detail.
Other famous rendering of Projective Plane include: Boys surface (of Apery), Boys (Bryant-Kusner) surface, Steiner Surface
If you have a question, put $5 at patreon and message me.