Empire Flexible Silicone Skin Glow in the Dark Green Case for T-Mobile Concord Specially designed Flexible Silicone Skin Glow in the Dark Green Case for T-Mobile Concord. 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.