Soldering Flux acts as a chemical cleaning agent to remove impurities from joint surfaces when soldering, ensuring a better joint. It has a non-acidic, non-toxic formula, offering fitters the benefits of savings, safety and certainty. WRAS (The Water Regulations Advisory Scheme) approved. Products compliant with this approval are accepted by all water suppliers in the UK. 1 x LA-CO Regular Soldering Flux, Size 125g Brush In Cap