I am installing vanity lights in a bathroom and the kit comes with 2 mounting plates: one level with 2 holes for screws and 2 one inch slots for screws, the 2nd is level on the 2 sides with the center inch being approx 1/2" deeper that the 2 sides. Do I need to install both the mounting plates? The instructions make no mention of a 2nd plate.
Thank you
Inge

You are given two different plates because they are sure of the box you have. You can use whichever one fits best. A picture would help.