Well, the Loree Rodkin diamond ring Mary Kate Olsen was spotted wearing in the front row at London and Paris Fashion Weeks isn't really a knuckle duster, it's more of a knuckle DUVET.

Though celebs Miley Cyrus, Rihanna and Kate Moss have borrowed the same style ring for the red carpet, our secret source tells us Mary Kate purchased her white gold and diamond "bondage" ring outright at her fave LA fashion haunt Maxfield.

The Maxfield store is so stealth it doesn't maintain a website and has only a cement facade for its entrance, but for those of you who are true red carpet style addicts, the boutique's phone number is (310) 274-8800 so you can pre-order the Olsen twins' high fashion line The Row to go along with your new ring.

Photos: Pascal Le Segretain/Getty; Chris Jackson/Getty