Ardex X3 PLUS Tile and Stone Gray Mortar is a polymer-modified mortar with good bond strength, sag-resistance and a 3-hour pot life. Ardex X3 PLUS mixes to a creamy, easy to apply thin set mortar that is water and weather resistant. It's formulated for large, heavy tile and stone, as well as ungauged thicknesses, and can be used to install quarry, porcelain, ceramic and most natural stone tiles.