temperature housing / box for thermometer/hydrometer bought on aliexpress
the batery-lid needs support.. the rest do not.
i used some battery spring contact plate replacement 14,5x9mm also from aliexpress. you can also use some wire as contact plate for the battery.
i made this for a Cessna 182TRG to get a more precise temperature outside when flying in different altitudes.
the temperature is measured from an air intake on the wing of the airplane.