Sonopanel CR9 is a "light" version of the X panels. CR stands for Cork/Rubber and the figure 9 indicates the density which in this case is 965 kg/m3. The cork/rubber combination has a very high airborne sound insulation value and also the radiation of the SONOPANEL CR9 panel is extremely low. CR9 panels provide excellent sound insulation. The panels are made in standard sizes as well as special structures. Our sound-insulating sandwich panels are used in motor and sailing yachts, buses and coaches, houses, offices, theatres and soundproof enclosures.