Nikon CFI plan 4X microscope objective for the current series of infinity generation of microscopes which include the E400/600/800/1000, the 50I/81I and the current CiL model. These have been lightly used and are in perfect optical and near perfect cosmetic condition. The current Nikon number is MRL00042 with a most recent list price of $173.00. The objective is infinity corrected with an NA of 0.1 and working distance of 30mm. It does not require Thank You For Looking!