Bostik Contact Bond is a type of adhesive. It is a multi-purpose, solvent-based contact adhesive that can be used for bonding a wide range of materials, such as wood, metal, glass, and plastics. It is typically used in applications where a strong and permanent bond is required. The adhesive is applied to both surfaces to be bonded, allowed to dry to a tacky state, and then the two surfaces are brought together to form a strong bond. The 4-liter size refers to the amount of adhesive in the container, and is suitable for larger projects or industrial use.