These are Master mercurial thermometers just over 30 cm long to reach deep into the incubator

Note the enlarged scales to be easily read and the grommet on the lower one to stop it falling into the incubator

This is not a Thermometer but a Hygrometer The temperature is an added extra. It can be set to display either ºF or ºC and the RH set to % or dewpoint, accurate too