This is an indoor module. It has the same form factor as the outdoor module except for the suspension device at the back. The product and the description here are correct. And no, so far there are no individual outdoor modules here at Digitec. Not from the manufacturer either, by the way.

The indoor module graphically displays the CO2 content and also shows the value of the CO2 measurement inside. The outdoor module measures the air quality outside. There are two indexes: Background (usually in the agglomeration) and Roadside (city streets). More information on the Netatmo website. In my case, the outdoor module is less high than the indoor module (as in the offer from Digitec in the basic set Netatmo NWS01-EC).