Novaking has good points there.
It's looks a bit too much DIY/experimental now.
And if you don't already have, I would put up a pack of matching (S&F) balls in your shop.
If you stack them closely with enough space and a mesh cube around it, it would make it easy for handling and shipping to make sure none go missing.
Perhaps also offer quarter/half-packs so people can mix and match colors.
The (short) description on your model page is a bit dry:
And on youtube you also have an elaborate description where the link is not visible in the shortened version.
As far as I can tell from my experience, long and elaborate descriptions are not very useful in promotion and sales.
I recommend adding only the following line to the youtube video description:
"Info and purchasing:
http://shpws.me/D6g"
And remix your current descriptions to a short and snappy one.
Perhaps followed by the more in depth description below the more button and a separate <h1> heading or similar.
I think the first four lines of text are crucial to making a sale or stir interest.
A twin-rail mobius pendant<br>
An endless and mind-warping cage for a train of 6 mm ball-bearings. Or better yet, or get the colored </link>supermarbles</link><br>
<h1>
What why how.
Etc
And then read it back as if you are completely new or find someone who is
Do the sentences read swiftly?
Is it to the point?
Does it say what you mean to say?
Cheers!