Accumet Materials, Co.: These hollow ceramic spheres range in particle size and type of coating. They enable design engineers to manufacture high-strength, lightweight parts and improve buoyancy, and thermal and acoustical insulation. They can replace traditional fillers such as silica, talc and calcium carbonate. Standard coatings include aluminium, magnesium and nickel, although other coatings, such as iron and tungsten, are also available. Complete coverage and adhesion is guaranteed, and the coatings are stable in air at room temperature.