DELTA® MARINE Board is manufactured in three (48 kg) through eight pounds (128 kg) per cubic foot (cubic meter) densities from mineral wool bonded together with a high temperature binder. It has been tested by Southwest Research Institute and approved by the United States Coast Guard with certificate of approval numbers listed below. DELTA® MARINE Board is thermally efficient, acoustically proficient, semi-rigid insulation designed for various marine applications such as insulating/fire protection for bulkheads, wall and ceiling assemblies, in addition to being suitable for ducts, mufflers, and exhaust stacks.