America's #1 selling latex caulk. ALEX PLUS® is a superior quality, all-purpose acrylic latex caulk plus silicone -Highly flexible and durable for a waterproof seal. -Excellent adhesion. -Cured caulk is mold and mildew resistant. -Easy to apply and tool. -Paintable. -Easy water clean-up. -Indoor/outdoor use. -Exceeds ASTM Specification C834.