This is for allowing an intermediate magnification adjustment prior to the final lens. The field-lens is removable and replaceable. Except for a few little nicks and a slightly eroding right-side rubber eye pad (photo), this equipment is in excellent condition. Wiring for electronic sensor is clipped but accessible for connection. It is a marvel of precision engineering.
I have no way of testing but do certify that all lenses are intact and undamaged; all the parts work as designed, and smoothly. There is no play in the fit. The binocular section alone work remarkably well as field binoculars.The item "Carl Zeiss F=125 Surgical Microscope Binocular Head plus 2 attachments" is in sale since Friday, June 12, 2020. This item is in the category "Business & Industrial\Healthcare, Lab & Dental\Medical & Lab Equipment, Devices\Microscopes". The seller is "jilaasc0" and is located in Sacramento, California. This item can be shipped to United States, Canada, United Kingdom, Mexico, Germany, France, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Greece, Portugal, Cyprus, Slovenia, Sweden, South Korea, Indonesia, South africa, Thailand, Belgium, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Austria, Bahamas, Israel, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica, Antigua and barbuda, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Saint lucia, Montserrat, Turks and caicos islands, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman islands, Liechtenstein, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Oman, Pakistan, Paraguay, Reunion, Uruguay.