fumi Acoustic Plaster® S1 is a non-combustible, cement-based dry mortar with lightweight mineral aggregates. With a grain size of approximately 0.3–0.5 mm, this plaster achieves a thermal conductivity of 0.12 W/(mK) and a sound absorption coefficient of up to alpha w 0.80, depending on the substrate. A layer thickness of 2–3 mm is recommended. This white plaster is primarily used on ceilings and upper wall areas in interior spaces, especially on acoustically effective systems such as perforated or mineral fiber panels, and serves as a sound-permeable finish. fumi Acoustic Plaster® S1 is available in white and comes in 50-liter bags. It belongs to building material class A1 (non-combustible), has customs tariff number 32149000, is suitable for damp rooms, and achieves a potential sound absorption coefficient of alpha w 0.80.