Case with filters?

I don't have the case. I've seen reviews though. The filters are removable. I suppose you could wash them but hand but its more normal jsut to blow them out with compressed air. Same as I do on my CM690II - the front fascia comes off with the filter and I just blow it out with air or now and then vacuum it with a brush head.
 
Corsairs filters are plastic mesh inserted behind steel grates (On the front) or plastic mesh inside a plastic insert for the bottom, with some foam in there as well.
These filters are best to be blown out with compressed air rather than washed. You may also replace them, but there is no real reason.
Source: I own the 300r, they use the same concepts.