STYLETHREAD -- LET'S TALK SHOP!

I got lucky and won this on E-bay!! Which is great, however I worry now that I will need an XS where I won a Small.  I knew several of you liked it, so if it doesn't work I will probably relist on Ebay.  Thought I'd share with my fellow Style threaders first, just in case any of you were interested.  Has anyone tried this on or seen it in person to give me an idea on the size??  Thanks ladies!!