HN504™ is a specially formulated tin/palladium colloidal catalyst that can render non-conductive surfaces conductive. The HN504™ Activator Bath is packaged as a two-component system. HN503 Pre-Dip is the aqueous carrier solution and HN504.2™ Acid-Free Activator is the metal-containing liquid concentrate. When mixed together, they form the operating HN504™ Activator bath. ALWAYS use FRESH HN503™ PreDip to mix the HN504™ Activator bath or to make additions to the bath.