Not sure where this should be posted on here, so I'll put it here and Mod's are welcome to move it if desired. Does anyone have a Katadyn Pocket Water Filter? I recently purchased one (or should I say took out a second mortgage for one). The filter has a green half circle plastic thing that fits halfway around the ceramic, but I have no clue as to what it is for. I have read all the paperwork and checked their website, nothing. Only thing I have found was in the parts blowup, it shows it as going over the ceramic filter. This must be for cleaning or something, because it cannot be put together with it on.