iSpring CU-A4 4-Stage Compact, High Efficiency Multi-Purpose Drinking Water Filter System for Sink, Refrigerator and RV - Removes Bacteria, Giardia, Lead, Arsenic and much more Superior 4-stage multipurpose water filtration system for safer, healthier, better-tasting water. The unique 4-stage design, which includes both UltraFiltration and KDF/GAC stages provides the most effective water filtration in its class. The 0.1 micron Ultra Filtration (UF) stage removes up to 99% of most problematic pollutants such as chlorine and chlorine treatment by-products, bacteria, giardia, lead, arsenic, and much more, while retaining healthy minerals. Simple, compact and flexible, the CU-A4 provides highly effective water filtration for any number of clean-water needs - at the sink, in the refrigerator, for coffee makers and more. With no storage water tank and no waste water, the CU-A4 is perfect even for RVs. Designed for high reliability, maximum flow rate and low maintenance, the CU-A4 uses High capacity cartridges that last up to twice as long as similar products. Can be installed inline and used as a fridge filter All filters, tubing and other water-contacting parts are manufactured to comply strictly with FDA and NSF/ANSI standards for safety and water quality. Simple to install and simple to maintain, CU-A4 Easy-Twist Cartridges simply twist on and off. iSpring supports all of its product with the best support in the industry. In addition to our 1-year limited warranty, we offer lifetime technical support provided by our dedicated, WQA-certified support team based in in Alpharetta, GA and available at (678) 261-7611.