Don't quote me on this, but these might have a metal wire that is used to close the grip on them (can you check Mark?).
I know some of them do, so be careful!
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=12755
I've used the second, clear pair of gloves, they always get water in them and I ende up tossing them out sooner then I thought.
The purple and red pair are a bit thick, but they work for me (just rinse them real well before use)!