Perforated painted 0. 019" aluminum with 7 rows of patented recessed louvers Fits 5" and 6" residential K- type gutters Designed for heavy duty hangers with the built-in screws; Screws to the front of the gutter and slips under the shingles Heaviest water load and maximum debris load, including pine needles and oak pollen Twenty five 4-foot sections; Will cover 100 feet of gutter