HYCON R 3660 F is a setting retarder in powder form. HYCON R 3660 F is especially optimized for retardation of the setting of ternary self-leveling underlayments based on CAC (calcium aluminate cement), OPC (ordinary Portland cement), and calcium sulphate (Anhydrite, or mixes of Anhydrite and Hemihydrate). In combination with the superplasticizer Melflux® SELECT 6030 F a dry mortar formulation with a reduction addition of Li-salts is possible. At the same time early strength development, storage stability, and temperature robustness of the system are improved.