RubberStop Weather-Resistant Silicone Sealant is made from 100% natural silicone rubber, making it permanently flexible and ideal for sealing roof and gutters under extreme weather condition. Compared to other sealants, it doesn’t shrink, crack, and become brittle after being exposed to sunlight for a long time. It has gone through a 250-hour accelerated weathering test and still exhibits outstanding flexibility compared to other sealants that become powdery or brittle. It can adhere to most bui