Yeah but last time I heard, a Klein bottle being only a one sided surface can only be rendered in 4D space with the 'passing through' funnel not breaking or intersecting the curved surface and this can't be rendered in 3D space. Unless recently they've decided to relax that restriction. Nice model though and worth getting but I wonder how best to mount it in a display case.
IE, cross-sections or projections. Would be interesting if there were a way to render a Klein bottle using techniques similar to those used when 'impossible triangles' are modeled with boards and 2x4s in fields which then seem to work when viewed from a certain angle. But then what would non-intersecting intersecting lines look like. Sounds like double-think.