EDGEHD 8"" and Baader Diamond Steeltrack Focuser Question

[Hogarth]

Hello

I wonder if some can advise on this

Long time refractor owner, first time SCT (EDGEHD 8") owner

I've bought the Baader Diamond Steeltrack external focuser and my question is

Does the focuser mount onto the thread as shown in the picture, or does that need to come off and mount flush to the back of the OTA

Thanks in advance
 

Edited May 1, 2021 by Hogarth

[Robindonne]

On my normal c8 i had a ring in between like on your picture.  But just to not scrape the black paint off of the c8 when attaching the focuser.