CBRP – Cool Blue™ Reusable Heat Sink Putty protects surfaces, valves and heat sensitive components by absorbing excessive damaging surface heat when soldering, brazing or welding. It is perfect to use during the installation of a sight glass, TXV valves, reversing valves, liquid line filter driers and ball valves. Cool Blue™ putty is reusable up to 40 times and is antimicrobial to prevent mold. If the putty ever dries out simply add a few drops of water and mix it into the putty to re-energize it.