Are you allowed to purchase Ammunition Links in CA?

[Walther_P99]

I don't know the law and I was wonder are ammunition links illegal to purchase to California? For example old surplus M60 metal links.

http://glocktalk.com/classifieds/showproduct.php?product=18204&title=m60-7-62-nato-links-sold-in-sets-of-100&cat=6