The AXEON HF4-3218 Reverse Osmosis Membranes are one of the industries most reliable and highest performing reverse osmosis elements. The HF4-3218 RO membrane elements feature a protective tape wound exterior, and are 100% vacuum integrity tested. Features: Superior Quality and Cost Savings Individually Inspected, Qualified and Vacuum Tested All Industry Standard Sizes Ultra Low Energy with High Flow Rates Improved RO System Performance