Klein Bottle

In mathematics, the Klein bottle (also called Klein wineskin) is a non-orientable surface, that is, a surface for which there is no distinction between "inside" and "outside". The Klein bottle was first described in 1882 by the German mathematician Felix KleinImagine a bottle with a hole in the bottom. Now extend the neck of the bottle, curving it on itself, until it is inserted laterally inside the bottle. This operation requires in three-dimensional space that the neck pierces the wall of the bottle, the operation can be done without touching the wall. Finally, connect the neck with the hole in the bottom. Boost MeEasy to print without using supports, I recommend using a transparent filament to have a better view of the inside of the bottle