Its a dry block calibrator, you basically set the termperature to whatever you want..say 66 degrees, put your thermometers, stc 1000's, thermocouple etc in the top and see what they're reading. Its accurate within 0.1 of a degree.
Im just waiting for it to be used in Perth and then im taking it home for the weekend to calibrate every 2 bit thermo device I own.
They only cost a gazillion dollars if you want to buy one, but there worth it.