Liquid Rosin Flux 4.2 OZ For leaded and lead free soldering. Fully activated. Offers superior fluxing ability. Instant wetting. After soldering, the rosin residue is non-corrosive, non-conductive, moisture and fungus resistant. Superior fluxing ability Instant wetting After soldering, the rosin residue is non-corrosive, non-conducting, moisture resistant, and fungus resistant Meets Mil.