The advance 4-stage design of this multipurpose water filtration system includes both Ultrafiltration and KDF/GAC stages. The 0.01 micron Ultra Filtration (UF) stage removes up to 99% of most problematic pollutants such as chlorine and chlorine treatment by-products, lead, arsenic, and much more while retaining healthy minerals. This system provides water filtration for unlimited free bottled water quality at your kitchen sink. Simple to install and simple to maintain, CU-A4 Easy-Twist Cartridges simply twist on and off. All filters, tubing and other water-contacting parts are manufactured to comply strictly with FDA and NSF/ANSI standards for water quality.