"OATEY" ROSIN CORE SOLDER0.125" gauge. 40% tin & 60% lead. Most common general purpose alloy n the core solders. Rosin flux is contained in the wire core. No external flux is necessary. Designed for electrical/electronic work. flux residue is non corrosive & non conductive. Use on wiring in stereos, motors, appliances, auto batteries, cables, etc. 1lb. Bulk.