Environmentally safe solder. This solder is designed to replace standard lead bearing solder for electronic connections. The reflow temperature is 217 Degrees - 219 Degrees C. The alloy is 95.5% Tin (Sn) / 4 % Silver (Ag) / .5% (Cu). This combination is the best for soldering electronic connections while retarding the dissolution of copper. It has excellent wetting and spreading properties. No clean flux.