OK, this one had me thinking.
http://www.ebay.com/itm/Vintage-Starter-Anaheim-Mighty-Ducks-NHL-Hockey-Jersey-Size-ADULT-S-M-/160955769112?pt=U_Hockey_Fan_Shop&hash=item2579b62118
It just says the size is Small/Medium instead of a number, and is "made in Korea."