Spectralock Pro Premium Grout is a patented, high performance epoxy grout which offers excellent color uniformity, durability, stain protection and beautiful, full grout joints in an easy-to-use, non-sag formula. Spectralock Pro Premium Grout is designed for use on ceramic tile, glass tile and stone applications, both residential and commercial. It can be used both interior and exterior on floors and walls. Ideal for re-grouting applications, Spectralock Pro Premium Grout is perfect for swimming pools, fountains and other wet area applications. Stainproof (residential installations only) to common household cleaners, liquids and other goods. Clean all spills immediately.