Nikon CFI Plan Fluor 100X oil immersion microscope objective for the Nikon E200, E400, E600, E800. E1000, 50I, 80I, and current CIL series of microscopes. It has an NA of 1.30 and working distance (WD) of 0.16mm. This objective is a new in every respect, however it was used as a dealer demonstrator. Thanks for Looking!