Quarter-Wavelength Filter on Stem

Description Retardation plate (?/4 platelet) made of plastic foil, rotatable on a ball-bearing in a holder on a stem. With an angle scale possessing 1° increments. Aperture: 38 mm O Retardation: ?/4 at 560 nm Height of the optical axis: 150 mm Holder: 100 mm O Stem: 10 mm O