MPERO Collection Flexible Silicone Skin Glow in the Dark Green Case for HTC One M7 Specially designed Flexible Silicone Skin Glow in the Dark Green Case for HTC One M7. 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. MPERO is a protected trademark.