Concrete products need to be sealed to protect against staining. While we use a world-class sealer on all concrete products prior to shipping, surfaces that incur significant use (e.g. countertops and tables) will tend to wear down and dull over time. If this occurs, we strongly recommend that you reseal your surface. Our Sealer Repair Kits are intended for re-coating worn or damaged indoor & outdoor Trueform Concrete products. Each contains enough sealer to cover 40 sq feet of surface area as well as some ancillary supplies to give you a head start. Use Sealer Kit 4 for smaller, detailed objects (sinks). Use Sealer Kit 9 for larger, less-detailed objects (tables, countertops).