Mapei Rapid Level CT 3220 Fast-Set Self-Levelling ScreedRapid Level CT 3220 is a rapid setting smoothing levelling compound for levelling differences in thickness between 3mm to 20mm in one application. It allows the installation of ceramic, porcelain and natural stone tiles in just 45 minutes. Where to use: For internal use only. For levelling, smoothing and infilling differences of between 3 and 20 mm in a single application. Suitable for levelling a variety of substrates including new or existing