UV15-7LRI is an optically clear UV curable polymer system formulated to have a low 1.481 refractive index. It produces durable, tough, non-yellowing, and chemically resistant bonds, seals, or coatings with excellent optical and electrical insulation properties. Its tensile strength is a significant 2830 psi and its specific resistance is 1x1016 ohm-cm. The UV cured polymeric material can be employed over the wide service temperature range of -50 to 150°C. Cured UV15-7LRI exhibits desirable properties including durability, toughness, and thermal shock resistance.