Airtight barrier locks out moisture, oxygen, contaminants-prevents Cu/ oxidation, preserves flux activity (vital for self-fluxing). Moisture/ for long-term storage BCuP-5 silver brazing rods work reliably in home and industrial use, ideal for high-strength, parts-air-conditioners, HVAC, refrigerators, freezers, compressors, motors-ensuring joints Solidus 1193°F (645°C), liquidus 1472°F (800°C), fluidity rating 3. 0.001"-0.003" joint clearance. Silver enhances fluidity, enabling into small gaps for stronger joints and faster brazing Contains 14-16% , 4.8-5.2% P, Cu balance. 15% boosts fluidity & wettability for seamless joints, reducing porosity & cold solder defects. Enhances shock resistance, extending lifespan of HVAC/refrigeration systems BCuP-5 needs no extra flux for copper-to-copper; use flux for copper-brass, copper-steel and other dissimilar metals. Clean surfaces with a wire brush first; wear heat- gloves and goggles, Weight: 0.19731372449 Pounds, Manufacturer: susaa