Sentinel 24-7 is a high-quality, acrylic-based coating with Microban® Antimicrobial Product Protection that inhibits the growth of bacteria, mold & mildew that cause stains & odors on the dried coating film – 24 hours a day, 7 days a week. 24-7 can be used on a variety of surfaces including, but not limited to lined and unlined exterior and interior duct systems, previously painted surfaces, wood, concrete, drywall, plaster, brick and most metals. 24-7 is self-priming, so a light precoat will prime most smooth wood or metal surfaces.