The GE Desal AK4021TF Dry Filmtec Style reverse osmosis elements are used for brackish water desalinationThe Desal AK4021TF RO element is tape wrappedThe A Series thin film reverse osmosis membrane elements are characterized by high flux and excellent sodium chloride rejectionGE Osmonics Desal AK4021TF High Rejection Brackish Water reverse osmosis elements feature a tape outer wrap and 28 mil feed spacers and is designed with male end connectionsGE Desal AK High Rejection Brackish Water Elements are selected when high rejection and operating pressures as low as 100 psig are desired Additional Details ------------------------------ Product description: The GE Desal AK4021TF Dry Filmtec Style reverse osmosis elements are used for brackish water desalinationThe Desal AK4021TF RO element is tape wrappedThe A Series thin film reverse osmosis membrane elements are characterized by high flux and excellent sodium chloride rejectionGE Osmonics Desal AK4021TF High Rejection Brackish Water reverse osmosis elements feature a tape outer wrap and 28 mil feed spacers and is designed with male end connectionsGE Desal AK High Rejection Brackish Water Elements are selected when high rejection and operating pressures as low as 100 psig are desired