Make sure you watch with the sound on. The noises are adorable!
The Klein bottle is my favorite manifold. (Everyone should have a favorite manifold; if in doubt, go with a torus — many delicious edible varieties.)
You can buy glass Klein bottles here. Also plastic ones.
WOOOW That Klein bottle/hat shop is deliciously nerdy. Tempted to purchase for my dad. :p
And apparently that pumpkin is just delicious… D’aww