The below pic is of the installed awning rail.

The below pic is of the left upper awning arm.

The below pic is of the left lower awning arm.

The below pic is of the right upper awning arm, you an see that the awning arm bracket rest on top of the trailer.

The below pic is of the awning above the door.

The below pic is of the right lower awning arm.

The below pic is of the awning rolled out.

The trailer is a 7 X 14 cargo trailer with a flat roof, the awning is a 12 foot awning with long arms.
The awning was installed per the directions of the A&E Domitic 8500 Awning.
The long arms were necessary to reach the lower part of the trailer were there is material strong enough to install the bracket.
You will need to measure per the awning measuring directions.
When the awning is rolled up, it is above the top of the trailer, this was necessary to clear the top of the door.
Also to provide clearance for the door, the awning rail was installed with the screws under the awning. The rail can be installed either way.
An awning roller was installed on the door so that the edge of the door does not rip the awning fabric.
When the awning is rolled out care is taken that the awning arms are extended to the point that the door does not swing out and catch the awning,
the long awning arms allow this to happen.
The install was not hard, just measure properly, and follow the install directions
I hope this helps, let me know if you have any question?
Johnnie