A klein bottle is an example of a non-orientable surface: it is impossible to mathematically assign an inside or an outside to the shape.  This non-euclidean geometry is a higher dimensional version of a more commonly known "mobius strip", and shows a representation of how the third dimension may warp through a fourth to endlessly cycle.  More information about it can be found at [ Klein bottle - Wikipedia ].
 
This model features a typical klein bottle, with a small glass sunflower marble created by Australian glass artist Michael Leeder [@michaels_glass_diary] mounted to the inner tube.  The model sits on a spiked foot with a black and yellow banded lip.