Leaf Defier is actually a leader in the foam insert gutter protection systems. This item comes useful , for it 's open cell polyurethane designs blocks all types of debris, small or large from getting into your gutters, while still letting water to flow through and down your gutter system. My boss is happy with Leaf Defier and its benefits. He wants this item to be installed on every gutter for every new school building project in 2013 . This is an ideal gutter install system for homeowners too !