If you are looking for plastic rings that you use to attach the handle of the purse to the body, I would think you could use the 2" rings that are used for macrame. I did a google search and this is the first thing that popped up.
http://www.ebay.com/itm/LOT-12-RED-2...-/370275222325 If these rings are what you are looking for, just do a google search for macrame plastic rings