Pleated cartridges. The multi-layer, fiber-based media of ARNS Filter pleated filter elements provide true depth-loading for high-efficiency removal at low micron ratings. Pleated depth cartridges design increases surface area, increasing loading capacity and allowing for higher flow rates. In a typical process flow, the pleated cartridges are used as a prefilter to pleated membranes or as a polishing element to depth-style media.