This square is a fundamental polygon of the Klein bottle.
Nonetheless, there is a way to visualize the Klein bottle as being contained in four dimensions.
This is an immersion of the Klein bottle in three dimensions.
The common physical model of a Klein bottle is a similar construction.
Thus, the Klein bottle is a closed surface with no distinction between inside and outside.
Building a Klein bottle which is not self-intersecting requires four or more dimensions of space.
The Klein bottle is an example of such a knotted surface .
Have you ever tried to figure out a Klein bottle?
The case of two copies corresponds to the famous Klein bottle.
The Klein bottle has a single continuous surface that passes through the bulb to connect inside with outside.