Sikaflex®-521 UV Weatherproof sealant free of isocyanates Sikaflex®-521 UV is a one-component, weather-resistant sealant based on Silane Terminated Polymers (STP) that cures upon exposure to atmospheric moisture. This multipurpose product is suitable for interior and exterior sealing applications. Resistance to aging and atmospheric agents Adheres well to a wide variety of substrates without the need for special pre-treatments Can be painted. **ADVANTAGES Resistance to aging and atmospheric agents Adheres well to a wide variety of substrates without the need for special pre-treatments Can be painted It can be sanded Low odor emission Solvent and isocyanate free Free from silicone and PVC. **JOBS Sikaflex®-521 UV adheres well to a wide range of substrates and is suitable for elastic bonding and sealing. Suitable substrates are wood, metals, metal primers and painted surfaces (2-component systems), ceramic materials and plastics. Consult the manufacturer and carry out tests on original substrates before using Sikaflex®-521 UV on materials subject to stress cracking. This product is suitable for experienced professional users only. To ensure adhesion and material compatibility, tests with actual substrates must be carried out.