NPT® 128578 1 gal Oceancare Glass & Tile Shield is an invisible, non-toxic, easy to apply surface protectant that inhibits the bond of calcium and other mineral deposits. Protected surfaces are easier to maintain and most deposits are removed with light brushing or scrubbing. This eliminates the need for abrasive or acidic cleaners and keeps your surfaces looking new, longer. Use on a variety of hard surfaces including ceramic tile, porcelain tile, glass tile, natural stone, windows, shower doors, metal fixtures, mirrors, tubs and sinks. Excellent for pools, ponds and rock water features. Dried product is safe for aquariums and marine life.