Abstract: A low temperature curable silicone rubber composition includes a polysiloxane mixture, a platinum group metal containing catalyst, an inhibitor, a crosslinker, and an alumina powder mixture in an amount of at least 85% of the weight of the curable silicone rubber composition. The alumina powder mixture of the invention includes two or more micronized alumina powders, and in particular, three micronized alumina powders. Advantageously, the silicone rubber compositions of the invention are curable at room temperature with both excellent calenderability and thermal conductivity thereby making these compositions excellent candidate materials for forming gap pads.