First, the great, Anna with customer service. Second, would be better to come with the internal rubber "bracket". If the corner brackets are missing, the screws likely ripped through the rubber brackets, requiring replacement also. I bought a used bike that had been dropped and had the corner bumpers torn off. Also missing from inside the bags was the rubber brackets the screws go through. Lastly, there are holes in the bag holding the corner bumpers likely for packing and shipping. Well, a screw fell out of the hole prior to shipping. Anna came through sending out replacement screws and brackets.