Gilera dna50 - what does this box do?

Hi, im trying to sort out some basic issues on a gilera dna50. Its a 2003 model and has a black box sitting above the stator on the offside of the engine bay. The box appears to have no inlet or outlet except a pipe at the top facing forwards which is capped off with a rubber bung. What is this box for? I have read that dna have two air filter systems and wonder if this is part of that maybe? I cant seem to get information anywhere.
Thanks

 

Its for the standard DNA exhaust system which circulate the air around the transmission.

 

Cheers mate