Rain Flow LLC, St. Clair Shores, Mich., offers Rain Flow, a new solution for clogged gutters. Made from recycled plastic milk containers, the product fills the gutter with a porous, synthetic fiber material. Shingle grit and other tiny bits of debris pass right through, while leaves, pine needles, seeds, twigs, etc., stay on top to dry up and blow away in the wind. Self-cleaning with every rainfall, it is invisible from the ground level so color matching is unnecessary. Four-foot lengths are easy to handle and cut with a utility knife. The product comes with a 20-year warranty in two sizes to fit 5- and 6-inch K gutters.