USP Roofing Granules are made from 3M Classic Roofing Granules and are designed to match the granule surfacing of U.S. Ply membranes such as DuraFlex, DuraWeld, SafeWeld, and USP 160. USP Roofing Granules are a unique, natural mineral product, the only type of roofing granule that meets the toughest test of time, weather and the marketplace. Our granules are dense and non-porous, resist ultra-violet light and are tough enough to stand up under handling. And they hold the long-lasting ceramic coatings added to create the ever-growing selection of colors demanded by the roofing market.