Effective in making concrete harder, dustproof, oil proof, acid-resistant and moisture-resistant. Inner Seal is an alkali activated chemical penetrating concrete sealer unlike any other product on the market. When Inner Seal is applied to a concrete surface, it soaks down through the pores of the concrete 118 to 114 inch. This product reacts with the lime in concrete. In the presence of moisture, it forms a hard, insoluble gel within the pores, thus closing the small voids. Unlike surface coatings, this is not worn down by heavy traffic.