A Mobius torus to lasercut out of paper and fold together. The SVG file was generated with my STL unfolding program, available from trmm.net/Unfolding_STL
Laser cut the green lines at low power to create score marks and the red lines at high power to cut the outline. Dashed lines are "valley" folds, which means that the two pieces come towards you. solid lines are "mountain" folds, which means that the fold comes towards you.