The GAP series gap-filling material is a low modulus (soft) and highly thermally conductive silicone rubber material used to fill large

 irregular gaps between the semiconductor component and the heat dissipating surface, eliminating the thermal resistance generated by air in order to facilitate the heat dissipation. 

The thermal gap material has good softness (compressibility) and can fill the variable gap between multiple components and the universal heat sink, 

while only causing extremely low pressure on the components.