Nikon Stereo Microscope Objective Lens Plan Ergo 1X  MMH31000. This objective lens is used on the Nikon SMZ800 and Nikon SMZ1000. According to the Nikon literature: "When using the ergonomic objective (Plan 1X ERGO) the instrument's eyelevel is adjusted to match your eyepoint precisely without changing the magnification or working distance. Ergonomic objective can be extended or retracted to adjust the eye level within a maximum range of 40mm." This item is new but not in original packing.