3M Scotchfil Electrical Putty Can be wrapped, stretched or molded around irregular shapes for a quick, smooth insulation buildup. Insulates non-flat surfaces such as fittings and valves. Electrical grade, rubber-based, self-fusing putty tape insulates connections up to 600V. Non-corrosive synthetic rubber with peel-off liner. Operational temperature range 32 - 176° F.