Rain Filter™ Green Gutter Filtration is a simple, do-it-yourself gutter protection system that helps keep leaves, debris, insects, and other pests out of your gutters, allowing water to flow through the gutter system, even during the heaviest of rainstorms. Lightweight and flexible, the Rain Filter gutter filtration system is specially shaped to fit snugly into your gutters, reducing your need to clean your gutters, and is virtually invisible from ground level once installed. Rain Filter is made from multi-polymer foam that is both lightweight and durable and is formulated to perform in all weather conditions. It contains a UV coating to protect from degradation from the sun, and a biocide and fungicide to help prevent the growth of mold and mildew in the product. It fits all standard 5" K-Style gutters.