Spire "SilverGrease" Thermal grease Spire "SilverGrease" Thermal grease, Thermal Conductivity 2.17 W⁄m-K, Temp Usage -50 to 170 °C, Thermal Impedance 0.06°C⁄W, Application: Thermal grease can be used on the rear side of the heatsink which has no thermal pad. It will improve the heat