ðiːz dɪvˈaɪsᵻz mˌeɪk ɪt pˈɑːsᵻbəl tə mˈɑːnɪɾɚ tˈɛmpɹɪtʃɚɹ ɪnðə tʃˈæsi, vˈoʊltɪdʒ səplˈaɪd tə ðə mˈʌðɚbˌoːɹd baɪ ðə pˈaʊɚ səplˈaɪ jˈuːnɪt ænd ðə spˈiːd ʌvðə kəmpjˈuːɾɚ fˈænz ðæt ɑːɹ kənˈɛktᵻd dᵻɹˈɛktli tə wˈʌn ʌvðə fˈæn hˈɛdɚz ɔnðə mˈʌðɚbˌoːɹd.
These devices make it possible to monitor temperature in the chassis, voltage supplied to the motherboard by the power supply unit and the speed of the computer fans that are connected directly to one of the fan headers on the motherboard.