Dice set with percentile modeled in a Steampunk theme. The dice range from 16mm to 24mm.

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.