Potentially stupid question - Accessory viewfinder

[Arbitrarium]

I'm looking at accessory viewfinders, and was wondering why this Braun one (see attached) has a focus scale on it? Does the viewfinder itself focus?

Cheers

 

[Jim Jones]

Many accessory viewfinders have a distance scale that tilts the finder down for close-up framing.

 

[Arbitrarium]

Ah, parallax correction! Should have realised. Thanks

 

[R.Gould]

Parralex correction, I have a 130 viewfinder for my Agfa Ambi Sillette, you focus the camera and then set the same distance on the viewfinder