PENTRA-PEL® (SI) Surface Impregnator with Advanced Micro-bonding Stain Protection,hardens, densifies, and seals with its reactive hydrophobic water-repellant properties,providing protection against most stains. Left untreated, water, oils and other liquids can easily penetrate cementitious substrates and natural stone, leaving unwanted stains and stubborn hard to remove deposits that can damage or etch the surface. PENTRA-PEL® (SI)is designed to penetrate, seal and protect porous and absorbent surfaces that are prone to water-borne staining, efflorescence, dirt and grime build-up. PENTRA-PEL® (SI) also reduces rust discolorations and oil and grease penetration. This strong protective barrier is also breathable, allowing the substrate to release moisture.