SOPRASOLIN HD is a multi-purpose self-adhered membrane composed of proprietary SBS-modified bitumen. The underside consists of a release film and a specially blended self-adhered bitumen layer. The topside is surfaced with an aluminum film. SOPRASOLIN HD is designed to waterproof around vents, chimneys, skylights, ventilation units, etc. SOPRASOLIN HD is recommended for repair work and all general maintenance work. SOPRASOLIN HD may be left exposed for up to one year.