BOSS Products 125 Multi-Seal Building/Construction Sealant is a multipurpose, one part sealant, formulated from a hybrid polymer. Boss 125 is a unique sealant and is free from solvents, silicone, isocyanates and other hazardous raw materials. Boss 125 cures on exposure to atmospheric moisture to form a highly durable flexible sealant. Boss 125 Multi-Seal has been formulated to offer outstanding primerless adhesion to most common building materials including vinyl, aluminum, steel, concrete, wood and glass. Boss 125 can be applied and tooled under most weather conditions and is paintable with most latex base paints. Boss 125 offers a long life reliability and when cured, this sealant stays flexible without tearing, cracking, drying out, or becoming brittle.