"It seems that in addition to batteries and battery grips, there are also counterfeit Nikon filters. 1kindphotography has a detailed article on what you should look for to make sure your filter is genuine. Always purchase equipment from authorized Nikon dealers (the "fake" Nikon filter was bought on eBay).
Read more on NikonRumors.com: http://nikonrumors.com/2012/02/26/how-to-spot-counterfeit-nikon-filters.aspx/#ixzz1nefLkb6t"