e/Klein surface

Information
has gloss	eng: In mathematics, a Klein surface, named after Felix Klein, is a non-orientable closed surface. A Klein surface is homeomorphic to a connected sum of a number of copies of the real projective plane. The case of two copies corresponds to the famous Klein bottle. The next case, the connected sum of three copies of RP2, is a surface of Euler characteristic equal to −1. Its orientable double cover is the genus-2 surface.
lexicalization	eng: Klein surface
instance of	e/Surface