Just like eggshell, the interface between heatsink and metal lid seems no gap. But microscopic imperfections in their craftsmanship create small gap for air. Those gaps act as insulators, inhibiting the transfer of thermal energy from high temperature components.
Thermal grease provide excellent gap fill function, and transfer heat to heat sink.
Our thermal grease is made up of specially designed particles, engineered to correct the imperfections. Those particles work by filling in the small air gaps and allowing for peak transfer of heat away from your components.