D70-M54F adapter

This adapter is designed specifically for the OAG-L. It is required if the OAG-L is used without an electronic filter wheel (EFW). This is how you achieve the required back focus of 55 millimetres. The optical path then is: Telescope - ZWO tilt adapter - ZWO OAG-L - this adapter - cooled ZWO camera (full-frame or APS-C)