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.

A planter for your bike! Make your green form of transportation even greener. Works great with small potted plants and flowers, and even large air plants. Encourage yourself to ride your bike more by giving your plant some sunlight. This will guarantee that you will have the coolest bike at the bike rack. Part of my wearable planter series, shown here printed in blue ABS, the same material as Shapeways' Grey Robust. This model is sold from Shapeways, and is only the 3d printed piece. You'll have to add your own cord, and directions are available here.