The Crayford focusers allow you to easily attach a viewfinder
A finder shoe can be easily mounted on Crayford focusers. Most OAZs have blind screws (grub screws) for this purpose.
The Baader finder shoe #2457000A is ideal for this purpose because of its rounded design. The finder shoe is secured with an M5 countersunk screw. We always glue felt pads underneath to prevent scratching of the OAZ.