Quality AM/Spectrum  membranes seawater reverse osmosis elements offer the highest productivity while maintaining excellent salt rejection these membrane elements have the highest flow rates available to meet the water demands of both sea-based and land-based desalinators. High rejection membrane suitable for most watermakers with 2.5 inch diameter 21" membranes - ref SW30-2521

Depending on stock we will supply either AM or Spectrum factory fresh - the best you can buy