ALEX PLUS® Acrylic Latex Caulk Plus Silicone is a professional quality caulking product formulated to last. It is an all-purpose adhesive caulk ideal for a wide variety of applications for interior and exterior use. ALEXPLUS® contains silicone, which allows for excellent adhesion and flexibility to resist expansion and contraction without cracking. It provides a waterproof seal and prevents air and moisture from passing through cracks and joints thereby improving energy efficiency.