BainUT did very well in his answer ------until he said that activated charcoal does not remove trihalomethanes. A very simple Goggle search shows all sorts of articles that assert that activated charcoal does remove most organic chemicals uncluding trihalomethanes, and also chlorine. The key here is to replace the activated charcoal when it is used up. With chlorinated water: that means when you taste chlorine. With the Vario, you can remove the red cap on the filter and replace the charcoal with Katadyn's Vario carbon replacement 2-pack. With other filters, you might have to replace the whole filter after about 6 months of use. Please note that not all microfilters have Activated charcoal.

I'm going to disagree with Angus, somewhat (again). This filter uses granulated activated carbon (GAC) as part of its filtration system. Activated charcoal is highly effective in removing chlorine from water and remains one of the principle means of doing so. Other ways you can remove chlorine: UV light, like a SteriPen, but it'll take anywhere from 22 - 45 minutes to do so, which is not feasible. You can also use chemicals, such as sodium bisulfate/metabisulfite, but that too is not feasible. In heavily chlorinated water, like that found in a swimming pool, you may have to filter the water more than once to remove the chlorine, but you will remove it assuming you're using a relatively new GAC cartridge. The issue with GAC and filters like this, and why I don't fully disagree with Angus regarding his answer, is that they do not remove trihalomethanes, which are byproducts of chlorination and are considered toxic over time in amounts greater than 80ppb (according to the EPA). For emergency use, however, this product would likely be fine.

There is no filter short of a reverse osmosis filter (not at all portable) or a still that will get chlorine out. You need something like a marine watermaker for that; you're not going to find a portable filter that will get chlorine out of pool water.