hmmm sorry I had another look, sorry it looks like it might sinceit's molded after that MP10 matrix, I must've been thinking of another one which came in various color variants I saw in ebay - it was meant as a pendant so had the rings to put a clasp to it. But still that (Mito Matrix) is one expensive price for such a tiny matrix, die cast or not, it's puny compared to the other Matrix iterations.
Clock wise from top - Matrix which came with Reissue Galvatron (g1 mold)- yes it comes with the chain bit , Matrix which came with the 2 pack - Cyclonus/Rodimus, MP 10 Matrix ( same mold as the Mito one ), MP 01 Matrix - all plastic, chromed only, 3rd Party Dr Wu matrix.
Milhouse your better off to buy any of the first two matrix variants for Maniaking and just add a clasp with chain to it - easily available at Lincraft stores. Coz then he can waer it like a necklace like how G1 Galvatron does.