Vulkem® SIL Pro Series is a 100 percent silicone, high-performance, non-sag sealant with exceptional movement capabilities that remains permanently flexible throughout the life of the sealant. Vulkem® SIL provides a 100 percent waterproof and weatherproof seal for windows, doors, siding, expansion and control joints, and more. It provides a superior seal on aluminum, glass, steel, vinyl, painted metals, plastic, concrete, stone, brick, wood, CMU block, EIFS, and more. It's suitable for plus or minus 50 percent joint movement and won't shrink, crack, or yellow.