DAP Ultra Clear Roof Waterproof Rubber Sealant is a crystal clear, elastomeric synthetic rubber sealant that stops and prevents minor roof leaks. It creates an invisible, ultra waterproof seal around roof fixtures and penetrations to keep out water, air and moisture, preventing damage. Crystal clear sealant is clearer than silicone, adheres to wet or damp surfaces, is water/rain ready immediately and has strong multi-surface adhesion. Ultra Clear Sealant may be applied in extreme temperatures of 0 degrees to 120 degrees Fahrenheit. Provides UV resistance and will not yellow or break down over time. It also stays permanently flexible and crackproof even in cold temperatures for a long lasting seal. Exterior use. DAP caulk and sealants provide durable performance for a variety of projects.