Like a comb jelly...or not. This symmetry is rare in nature. Actually I don't know of any creature which has it. In two sizes, a little bigger for plastic and steel, or a little smaller for precious metals.
To hang well as a pendant, this needs a little extra bridge. This model doesn't have that, instead it is perfectly symmetrical. If you're not planning to wear it, or if symmetry is the most important thing, this is the one you want. With the bridge is here.
And it's here
as a handheld sculpture.