Rex CSS Glass & Tile Sealer™ is perfect for all glass surfaces. Just one treatment every 3 to 6 months will maintain the initial application to last a lifetime. Rex CSS Glass & Tile Sealer™ is engineered to never build up or discolor when applied properly. This long-lasting, invisible coating will protect your surfaces from hard water and limescale buildup. Avoid use on metal finishes or hardware coatings.