This is an AMAZING VINTAGE 300X magnification C-mount industrial microscope lens from Edmund Scientific from the 1980s.  This lens is monocular and is intended to be attached to a camera or digital display while held on a stand.  It comes in 2 parts; the long objective that can magnify up to 3X and the attachment lens that can magnify 10X.  It's clean and works perfectly.  It even has the original lens cover.  It is in EXCELLENT CONDITION!  This lens has been rarely used.  It's been stored in a plastic bag to keep it dust free for more than 20 years.  I comes in its original cardboard box.