Ultraflex RS is a premium-grade, single-component, high-performance, polymer-modified, rapid-setting mortar for ceramic tile, porcelain, marble, granite and slate installations. Formulated with MAPEI’s unique High-Hydrated Cement Technology (HCT™), Ultraflex RS is designed for fast-track projects and installations. It can be used for both interior and exterior installations of tile in most residential floor and wall applications. In commercial applications, use on interior floor and wall installations and exterior floors. Available grey in 25 lb and grey and white in 50 lb.