Heat sink draws heat away when applied to a component. Use Heat Sink compound to thermally bond a component with a mechanical heat sink. Used with thermocouple wells, thermistors and calrods for efficient cooling in electrical applications. Thermal conductivity – @ 36° C., 0.73 BTU inch/Hr. Ft. 2 °F. Functional temperature range -67°F to 401°F Non-ozone depleting. Will not harden and crack. Use TechSpray TESP-1978 Silicone Free where silicone contamination hurts solderability and increase solder defects. 4 Oz. tubes.