The lens in the photo is the 350 mm FE lens made specifically for the 201/203/205 series camera. Officially, it is a Zeiss Tele-Tessar FE 4/350 mm. The 4 indicates the maximum aperture opening of F4, a very fast lens. Although Hasselblad made a 500 mm lens, it was only F8 and did not have the electronics of the FE camera. They also made a 350 CFE lens, which did have the electronics, but was a slower F5.6 lens. Because the FE cameras have a focal plane shutter, the 350 FE has no shutter which is the reason it only works on the three FE cameras. Like the FE camera, most of these lens have been discontinued, are only available used, and are very hard to find. For digital usage, the 350 lens effectively becomes much longer because the 36 mm sensor captures only a portion of the 60 mm original film size; almost 600 mm!