9.5cm = 3.7" therefore you would use a filter with a 3.5" outlet. Obviously the outlet on the filter needs to be slightly smaller than the diameter of the rubber hosing, else if it is the same or larger it won't fit!
![Wink :wink:](./images/smilies/icon_wink.gif)
Once you have inserted the solid plastic outlet of the pod filter into the rubber hosing, you then tighten the round clamp that is around the rubber hosing, to make sure everything is nice and tight and stays in place.
Alternatively, if it is too hard to find a pod filter with a 3.5" outlet, just get one with a 3" outlet and use an adapter, as described in a previous post.