I have a ZWO OAG-L and I wish to fit a filter drawer between it and my ASI2900MC camera. The camera side of the OAG-L has no threads and adapters (or a filter wheel) are attached by screws. The images of M54 Filter Drawer shows holes in the circumference of the telescope side. Can someone tell me if four of these holes match the holes in the OAG-l and if so are they threaded? I do not want to buy the Filter Drawer only to find I can't fit it.
Many thanks
John
