Zeiss Distagon 28mm f2 ZF.2 for nikon F. The previous owner told me that the electronic contacts don't work. I can't check this, as I used it on Nikon FE2, FM2 and FA, which do not have any electronic contacts with the lens. It worked faultlessly on those cameras. But if you want to use it on DSLR, I cannot guarantee it works well. The optical part of the lens is very good.