For use in display cabinets where silverware may be kept. Each capsule provides protection from tarnishing for a 2ft radius (volume of 33.4 cubic feet). Capsules consist of a vaporising substance containing a mixture of organic ammonium nitrates of varying vapour pressures, a chemical system for neutralising lead acids and a volatile concentration of antioxidants. Should not be used with soft stone settings. Estimated life span of capsule once removed from sealed sachet is 12 months. Capsule size: 54mm x 32mm x 23mm