ᐅ IKEA UTDRAG Recirculating Range Hood Installation Issue

Hello everyone,

First of all, hello to everyone, I hope someone here can help me.

We bought a kitchen from IKEA and assembled it ourselves, everything went well so far. I just don’t quite understand something about our Utdrag recirculation range hood.

What is this part for? And is it necessary? Our package only included one, and the nearest IKEA is 80 meters (50 miles) away.

Without knowing the part, it looks to me very much like a filter for the recirculation system (activated carbon?).

This is a one-way flap that prevents air from the exhaust hood from escaping (wind from outside). Air can only flow in one direction. It should consist of two semicircles; otherwise, the system will not work.

I’m not sure if this part makes sense for recirculation mode.