Balco Acoustical Joint Seals and Partition Closure Seals are compression seals made from either foam or premium silicone, designed to fill the void between partition walls and exterior facades, curtain walls and cladding in multi-story construction, like hospitals, hotels, office buildings, etc. The seals provide vital movement due to thermal changes of exterior surfaces, while also serving to dampen sound transmissions. Simple design, easy to install, flexible, long-lasting.