These hidden gutter hangers or brackets will retro fit into existing gutters or can be used to install new gutter. They are formed to be one of the strongest brackets used in the industry. This is the bracket the professionals use.
Almost all aluminum gutters have a formed top front edge. The forming process imparts stability. Putting several closely spaced bends in the sheet aluminum gives it significant strength. Without the bends, the metal would be as flimsy as a wet noodle. The J shaped end of the hanger fits under the top front edge of the gutter and locks in place. 60 to 100 brackets are used on most homes. These brackets are mill finish but they are hidden inside the gutter so color is not an issue.
Consider placing gutter hangers every 24 to 36 inches for most applications