
Screws included #8-32. They fall into the threaded holes in the cast body. The included grounding screw begins to engage the threads approximately 1/16 inch before seating on the flange head. Running a ground wire underneath is not enough. The holes in the molded case appear to be M4.5. The M4 or #8 screw is too small. Screw #10-32 or M5 is too big. standard screw. This is hanging by the window upstairs, working on the boxes installed on the outside of the house. Basically, the quality control is not running, sort out parts.

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