Nikon EARLY NAI pre-AI f2.8 135mm manual focus lens.

First made in 1965, this is a slightly longer telephoto lens. It has a fast f2.8 maximum aperture and a built in lens hood. This is the first variant of the lens, with the earlier lens coating and a serial number between 135001 and 367229. Two versions were made with 'Nippon Kogaku' and 'Nikon', this lens is the earlier 'Nippon Kogaku' version. Will fit on some Nikon DSLR cameras. Depending on the model of camera, the exposure and metering maybe affected. It should not be fitted to a camera that has a non-removable AI tab. For full details, see the Nikon chart: https://nikoneurope-en.custhelp.com/app/answers/detail/a_id/19026 and this website https://www.bythom.com/lensacronyms.htm/