Gonioprism 4-mirror posner diagnostic and surgical lens
General Description
Posner diagnostic and surgical lens; gonoprism w/octagonal handle; silver surfaced pyramid forming 4 opposing mirrors set at 64 deg; aluminum handle set at 35 degrees bonded to one corner of lens; entire 360 degrees angle can be observed by rotating the lens 11 degrees in either direction; posner design for diagnostic and surgical use
