A theorem walks into a bar...
The Klein Bottle is a mathematical joke: a surface with only one side. This one feels just right in your hand and opens bottles with ease and style. Built to last in steel, it's the perfect touch for any math fan's kitchen.

Yes, it really works!

Klein not-a-bottle-opener is here.

Intricate Skull Cage, successfully printed in WSF & Antique Bronze. Available for the low price of $39.99 only on Shapeways during the Holiday season. :)

This full color ring is one for the cocksure guys and girls. Size US 7, 17.3mm