The GE Desal AK4021TF Dry-Filmtec Style reverse osmosis elements are used for brackish water desalination. The Desal AK4021TF RO element is tape wrapped. The A-Series thin-film reverse osmosis membrane elements are characterized by high flux and excellent sodium chloride rejection. GE Osmonics Desal AK4021TF High Rejection Brackish Water reverse osmosis elements feature a tape outerwrap and 28 mil feed spacers and are designed with male end connections. These elements allow significant energy savings.