Yes as you have found out it is the heraldic symbol associated with Brittany, essentially it is an ermine's (posh weasel) tail not sure what the three circles are :0)
and for those that are interested here are the pins, the bottom two are not yet finished:
http://farm9.staticflickr.com/8315/8...0656ed5f98.jpg
Pin collection by kwant, on Flickr