Parallel-sided coil with remote return tube, the inlet and singularity at the same end. When cut gives a 17-twist Mobius strip.
A single surface model made by Alan Bennett in Bedford, 1995. It consists of a parallel-sided coil with remote return tube with the inlet and singularity at the same end, which when theoretically cut gives a pair of 17-twist Mobius strips. A Klein bottle is a surface which has no edges, no outside or inside and cannot be properly constructed in three dimensions.