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. It applies crystal clear and stays clear for a seamless blend with substrates. Ultra Clear Roof can be applied in adverse weather conditions such as on wet or damp surfaces, through standing water and in extreme temperatures of 0F to 120F. It provides outstanding UV resistance so it wont yellow or break down over time. It stays permanently flexible and crack-proof even in cold temperatures, for a long-lasting, durable seal.