The Classic Composition, the industry's best-selling solar panel mount for rooftop solar installations of PV and solar water heating systems, uses our patented QBlock Elevated Water Seal technology to ensure a long, watertight life on composition/asphalt shingle roofs. The Classic Comp was also designed to install fast, with just a single bolt. It is backed by solid engineering and certified for strength and waterproofing by the ICC-ES. The Classic Composition Mount is the most universally code-compliant mount available for composition/asphalt shingle roofs.