OSI® Pro-Series® GS-121™ Gutter & Seam Sealant is excellent for sealing seams, joints, and cracks in gutter troughs, and will bond to any clean surface.

GS-121™ Gutter & Seam Sealant may also be used on sheet metal work, air conditioning, heating ducts, ventilators, etc. This product can be easily painted and will not lose its strong waterproof bond.