From the brand Product description Lead-free solder wire: Lead-free solder wire with rosin core; Our solder has good solderability in terms of electrical conductivity and thermal conductivity; The solder wire is made of high-quality materials, free of impurities, safe and reliable, and can be used for a long time. Lower melting point: The melting point of the solder wire is 227℃. Flexible and thin wire, ideal for home welders. The solder wire spool allows for quick soldering. Weight and diameter, the diameter of this lead-free solder wire is 0.8mm; Net weight: 50g; Sn 99.3% -Cu 0.7%; Flux content: 2.2%. Lead-free tin: Leaded solder, although very easy and convenient to use compared to lead-free, is terribly harmful to health and the environment. Avoid lead-related health problems and give up old habits. Very economical: Using solder in a roll is much more economical for you than buying it in small containers. In addition, you do not need to buy additional flux or rosin with the set