Wollensak Velostigmat Series II 9 1/2,Amazon.com : 241.3MM 4.5 WOLLENSAK Series II VELOSTIGMAT,Amazon.com : 241.3MM 4.5 WOLLENSAK Series II VELOSTIGMAT,Wollensak Velostigmat Series II F4.5 Focus 71/4,M42 MOUNT SPIRAL: Wollensak Dumont CRO Oscillo-Raptar 50mmF1.5*