Barbara the metal used for the brackets is 1-1/8" Wide x 1/8" thick.
The bracket is actually 2 pieces and they are attached together by one of the bolts that goes through the inside of the awning at the back.
The top pieces is 6 1/4" long in total and the section that is flat to the roof of the trailer with the bolt through into the inside of the trailer is 1 1/4" - the center of the bolt hole is a 1/2" from the end edge.
The lower piece is 4 1/4" long in total and the section that is flat to the trailer is also an 1 1/4" with the bolt (goes though into the trailer) centered 1/2" from the bottom edge. It is bolted onto the inside of the awning at the back with 2 bolts.
The whole awnings sits with the bottom back edge about 3/4" of an inch off the trailer.
Acorn nuts where used on the ceiling on the inside of the trailer where the bolt comes through - it also has a large washer on the inside under the rat fur.
As mentioned previously make sure you install it with butyl tape - mine wasnt and in heavy rains it dripped inside a little bit from 2 of the bolts - its been fine since it was redone with butyl.
A few more photos as the previous one was taken in the dark. Sorry about the glare but even though my old trailer is undercover it cant help but show off its shine! And guess what Its Not Floor Wax!