ULTRA FLUX PASTE 16 OZ BRAZING SILVER SOLDERING JEWELRY MAKING REPAIR METAL .- Size: 1 lb/16 Oz.(454 g.). jar .- Effective Range: 1100 to 1600 F . -Composition: Potassium salts of fluorine and boric acid .- Type: Paste - Particle size # 325 mesh or finer .- PH: 8.0 .- Flux is removed with hot water