Leaf Filter gutter guards have a serious design flaw. In heavy rain they cannot handle the flow that comes down from the valleys where two planes of the roof meet, so the water overshoots the gutter and falls to the ground - exactly what gutters are supposed to prevent. I called the company back, and the technician said that was what they were designed to do, to "let the system breathe", which is is nonsense. He then offered to put up vertical baffles at the points where the flow comes down, but said they would require cleaning from time to time - exactly what we bought Leaf Filter guards to avoid. He did that, and now the water backs up and comes down between the gutter and the fascia board. In time this will rot the fascia board. I am seriously disappointed in this product, and regret buying it.