There is no exact information. I believe that no more than a few thousand copies. The lens was announced in August 2003, but discontinued already in the first half of 2007 or even earlier. LTM and 1st gen. SL lenses were not produced in large quantities. Most of these lenses were bought by Japanese buyers during the so-called Japanese rangefinder revival of early 2000s. For example, using the Voigtlander FS adapter, the U-W HELIAR 12/5.6 ASPHERICAL SL could be mounted on the Cosina’s BESSA R2S rangefinder camera introduced in 2002.