The matter compressor was a device which compressed matter. Two Slitheen plotted to use a matter compressor to crush the carbon in Earth's atmosphere into an extremely massive and valuable diamond. However, one of the Slitheen sat on the compressor so they had to steal one from the Pharos Institute. They were tracked down by Sarah Jane Smith and her gang. She tried to use her sonic lipstick to disable the compressor, but it was sonic wave-resistant. K9's photon beam had no effect either. However, two Blathereen arrived and disintegrated the compressor. (TV: The Gift)