sorry if the Q is in wrong section

on w202 & w210 in left corner of the cars under the hood (pictures) what is ?

cabin air filters aren't because they are under glove box,battery on w210 is not because it is under back seats!

http://www.slike.hr/slika/4lo7y4x-f2644.jpg.html

http://www.slike.hr/slika/1-0c9fb.jpg.html

thanks

 

Those contain the vehicle's CAN (Controller Area Network), which has the ECU and various onboard CAN/computer modules plugged into it. There should be no servicing required, which is why the boxes are such a mystery. Not an unusual question at all.
Cheers,
Jeff