Yes, the K-Slim coffee maker has a spot for a charcoal water filter located at the bottom inside of the machine’s rear water reservoir. The Keurig Slim uses charcoal water filter cartridges measuring about 2 inches long and 1.12 inches tall. This small charcoal filter sits inside a BPA-free, clear plastic filter handle (sometimes sold separately from the brewer), which is then placed inside the water tank located behind the brewer.