meissner tetrahedron

This is a mathematical shape that will have equal distance between two flat surfaces when it rolls.  Put three meissner tetrahedrons on the table and a book onto this three, when you rotate the book horizontally, you'll find the meissner tetrahedrons roll like a sphere.  It acted like a sphere but not a sphere.
I can 3D print it as different sizes, from 2cm to 30cm. The showing one is 6cm.
My printing quality is good enough not to polish it.