Sonitus Acoustics diffusors are made of hard expanded polystyrene (EPS). Diffusors are used to make sound dispersion in your room, so that you get a similar sound energy in all parts of the room. Often used in home cinemas to get the same sound field for all listeners in the room at different positions. Sharpfusor and Fourfusor are 1D diffusors, also great for removing flutter echoes in spaces where absoprtion is not needed anymore. Installing the panels vertically and horizontally provides multi reflection. Low weight makes it easy to install on walls or ceilings.