The adapter allows the connection of M68 accessories to telescopes or proofreaders with M63x1 inner thread.
Example: The adapter fits 2.5 "-Okularauszüge with the M63 threaded connection (Starlight 2.5" Feather-Touch, TS 2.5 "Pinion and APM 2.5" pinion). It allows the use of M68 accessories on these focusers.