Chris, you might want to ask your question directly to Kohler via their website. They were very helpful with questions I had before purchasing this faucet. I’m not sure if there is a water filter for this model. The end piece is the pull down spray arm and spray control buttons. Any attachment would have to go above that I would think and might interfere with the hose. Sorry I could not help you. By the way, I did a huge amount of research before purchasing this faucet, and I love mine. When you first turn off the water, there may be a few drips but it is most likely accumulated water in the end of the spout. Just press the button to release residual water or wipe its “nose” with a paper towel (sorry, that’s the best way I can describe the drip). If it is annoying, Kohler will send you a fix as apparently this was an issue in the past.