The Waterdrop Water Faucet Filter adopts selected and tested Activated Carbon Block (ACF) that features large surface area and a lot of microholes to effectively adsorb harmful substances present in the tap water, leaving you with pure drinkable water. Tested and certified by NSF International against NSF/ANSI standard 42 for the reduction of 94.2 percent chlorine, taste, and odor, and NSF/ANSI 372 for lead-free material. You are ensured of a safe and reliable drinking experience at all times. Works with standard faucets.