DiamondClear™ HV is a high-viscosity windshield crack repair resin for use in hot weather, especially in bulls-eyes and combination breaks. It conceals vinyl damage caused by sever impacts. However, DO NOT use DiamondClear™ HV when radial cracks exceed 1/2". In such cases, use DiamondClear™ MV resin. Ideal temperature range is greater than 85 degrees F. British Standard Institute (BSI) Tested.