I have a 40 breeder that I converted into an AIO peninsula. I'm replacing my black box with the Reef LED 50. I will be building a DIY arm mount from square tubing as the Red Sea mounts do not come out far enough to center since it has to come out long ways past the filter section on the 40 breeder. I can't seem to find the screw size on the Reef LED 50 listed anywhere. I imagine it's a small m size thread.