100% Silicone Sealant for Long-Lasting Sealing: Formulated with pure silicone for exceptional elasticity and durability. Ideal for sealing joints and gaps on windows, doors, kitchens, bathrooms, and more. Flexible & Crack-Resistant Over Time: Once cured, it maintains its elasticity and resists cracking, discoloration, and shrinkage. Making it reliable for long-term indoor and outdoor applications. Excellent Adhesion to Non-Porous Surfaces: Bonds well to materials such as glass, ceramic, enamel, aluminum, stainless steel, painted wood, and various plastics. Suitable for professional and home use. Waterproof & Weather-Resistant Performance: Provides a watertight seal that withstands exposure to water and extreme weather conditions, perfect for areas exposed to moisture and temperature changes. Wide Application Temperature Range: Recommended application and surface temperatures: +41°F to +104°F (5°C to 40°C). Store in a cool, dry environment between +41°F to +77°F (5°C to 25°C) for optimal shelf life and performance. Stanley S421 All-Purpose RTV Silicone Sealant is a professional-grade, one-component silicone caulk designed for durable sealing across a wide range of surfaces. Featuring acetoxy cure technology, it offers fast skin formation, high elasticity, and excellent resistance to aging and discoloration. Ideal for sealing joints and gaps in kitchens, bathrooms, windows, doors, and various non-porous surfaces, this sealant provides strong adhesion to materials like glass, porcelain, coated wood, aluminum, and steel. Its waterproof formula makes it suitable for both indoor and outdoor use, including high-humidity and temperature-variable environments. Stanley S421 cures to a flexible, long-lasting finish that withstands exposure to water and the elements without cracking or degrading. It's a trusted solution for both DIY projects and professional construction or repair work.