This dummy head is used to calculate dosimetry (according to wikipedia: the measurement of doses in matter and tissue from ionizing radiation); this head is called SAM (acronym of something I forgot). It's made up to measure the SAR = energy absorbed by a body receiving mobile phone emissions. This head adopts the morphology of the human head and is filled with a gel that "possesses the electrical characteristics of the human brain" (vow our head is filled with gel, isn' it?).