Sonde found

It is not necessary to send us back.

In fact, the “box” you found is a meteorological radiosonde. This instrument, attached under a balloon inflated with helium gas, can reach 30 km altitude measuring temperature, humidity, pressure, wind speed and wind direction. All these data are transmitted in real time to a ground system and are very useful for meteorologists to establish forecasts. Reaching 30 km altitude, due to lack of pressure, the balloon bursts and the radiosonde flies down with its parachute.

Proceeding for environment protection :

- Take off the 4 batteries (the batteries are inside the box, open the little trap-door on the side of the box).
- Put the battery, the balloons and the box in adequate dustbins.

Doing so, you have contributed to environment protection and we are really grateful for your help.