OB1 One Tube, Multiple Jobs. The Revolutionary Hybrid Polymer formulation which bonds and seals almost everything and works in water. OB1 Multi-Surface Construction Sealant & Adhesive replaces mastics, wood and PU adhesives, silicone, sanitary sealants, acrylic and butyl rubber sealants all in just one product. Our highly environmental accredited product is one of the only products to meet consistently with the ever changing environmental legislations and it is V.O.C free, EC1+ Rated and Food Approved. Contains no isocyanates, silicones or solvents therefore it has been approved for Leed Construction Projects.