The Glass only measures 28 3/8" not 28 5/8 so my 29 1/4" rough opening they said would fit it way too big for the opening side L channel. Leaving me a 3/4" gap for water and air to get out.  Looks great, just doesn't fit well for the size advertised. Picture shows measured from the wall hing and glass.  28 7/8 should be the larges rough opening for this size.