This is the folding counter top bracket as its lifted the fold center will lock.
To release lock you lift shelf slightly and lift with fingers either side than drop shelf.
The shelf will be mounted on folding bracket the distance of your main counter overhang so both counter and shelf are flush across surface of counter.
Top corner of bracket will be mounted flush to counter overhang underneath.
I put one in my 99 MA simple mount.
Newmar may have asked for your Vin# or coach build number to match your counter trim.
You will like it makes for more room beside sink.