A set of FIVE dice in this item: d4, d6, d8, d12, d20. Each die is realized by a "skeleton" (See Sylook''s shop at https://www.shapeways.com/shops/the_shop_of_small_wonders for the idea behind it), with a wireframe model of the *dual* of the relevant polyhedron surrounding the skeleton. The numerals are affixed to the wireframe, which is free to move around on the skeleton--but not too far. Hence the name "rattling bones." (The d4 is a little different; the numbers are on the ends of the skeleton)
So far, has been canceled in steel (antique bronze glossy. reason: Loose parts can't be kept loose without breaking) and in Alumide (reason: Thin wall)