The Sika Aktivator-205 is a solvent-based, colorless adhesion promoter in a 1L clear bottle. It interacts with moisture to create active groups on non-porous substrates like metals, plastics, ceramic prints, and painted surfaces, serving as a bonding agent for primers or sealants/adhesives. This product is intended for use by experienced professionals for treating bond surfaces before applying Sikaflex and Sikasil products.