Optigen is accusing Joint Vision Manufacturer, a Chinese company it says is linked to Wenzhou Deheng Optical Company, of copying its internationally patented titanium memory metal frames and of exhibiting the counterfeit models at the Wenzhou optical industries booth during the 2009 edition of Mido in Milan. Optigen states that it was able to seize a few of the counterfeit models with the help of the Milan fairground's anti-counterfeit division. The Chinese company claims that the related patents have not been filed in China, and that it is thus within its rights to export the models to Europe. Optigen has consequently warned European importers against distributing models covered by the following patents: U.S. ? 6,565,207; US ? 6,557,993; GB ? 2 371 809; EP - A -1 099 134 A1; EP - A - 1 360 540 A1; DE - 101 39 961 A1; CA 2,337,474; IT 0001324064. The Italian company also states that there are currently only three Chinese manufacturers licensed to produce its memory metal frames: Okia, Star Spring and Lucheng Foreign Trade.