Product Description
The ZWO M54 adapter is an adapter designed specifically for ASI cooled cameras. Instead of using the 20mm ZWO EFW, you can directly connect the adapter to OAG-L to reach 55mm back focus.
It has a thickness of 15mm. You can also insert an ZWO 2”filter into it.
The best solution of 55mm back focus length
Please note the following solutions are premised on that you are using the OAG-L with the cooled camera.