Nokia Lumia 820 Case, Empire Flexible Silicone Skin Glow in the Dark Green Case for Nokia Lumia 820 Specially designed Flexible Silicone Skin Glow in the Dark Green Case for Nokia Lumia 820. Made from fully treated silicone. No mixes or blends. Chemically stable, even when impacted by heat or environmental impact. Insoluble in water, corrosion resistant, a virulent insipidity. EMPIRE is a registered trademark with the USPTO.