Sehr seltenes Exakta 80mm F/2.8 MC Schneider Objektiv Exakta 66 #14419347, Pentacon Six
It appears that this lens was manufactured by Joseph Schneider (Kreuznach). The design matches that of the Schneider lenses for the Exakta 66. Its serial number follows Joseph Schneider conventions used with other lenses for the Exakta 66.