I've seen thousands of dual/triple aperture scales to include hundreds just on Copal #0 shutters but I've never seen one like this with max apertures of f/5.6 and f/16. This would indicate a doubling of focal length if for a convertible lens or the shutter was intended to be shared between two different sets of cells.

Does anyone know what lens(es) this scale is for? As you can see the front scale is blank.