Nippon Kogaku Japan NIKKOR-S Auto 1:2 f=5cm (50mm) camera lens, No. 542119, with Nippon Kogaku case.

This lens was introduced with Nikon's first single lens reflex camera, the Nikon F, in June 1959.  Serial number range is 520001 - 584394 (last known serial number). Its production terminated in January 1964.

Focal length is 5cm (50mm).