The Mamiya Adapter Ring for the Polarizing Filter holds the special polarizing filter in place on the lens. The polarizer shifts vertically from the shooting position in front of the lens without changing its polarization rotation to cover the small square window, which contains the metering cell above the lens mount.
The polarizing filter is compatible with all Mamiya 7 lenses, (both 58mm and 67mm filter diameters) and mounts bayonet style on the front of the lens barrel in the same manner as the lens hoods supplied with each lens.