This is my first order from shapeways. These are reuleaux trianlges(commonly used in rotary engines) rotated about one of its vertices. The interesting property of this shape is its ability to roll just like a sphere, meaning that it has a constant width regardless of orientation. I am very pleased with the results. Sorry for not giving any sense of the scale. They are about the size of a quarter. Here is a link to my shop: http://www.shapeways.com/shops/greatgeometers.