The LACO Aluminum Flux & Solder Kit solders aluminum easily. Also solders aluminum to copper. Ideal for repairing leaks in HVAC systems. Includes: 1 Oz. aluminum flux paste and 1/2 Oz. solder. Low-temperature soldering prevents aluminum components from melting, New aluminum HVAC components will not stall job completion, Resists electrolytic action between aluminum and copper, preventing leakage between dissimilar metals, Includes 90/10 tin-zinc solder, keeping work conditions lead-free, & Made in USA.