Wine Filter City provides both pre-filters, which are typically constructed of pleated polypropylene microfiber and final membrane filters, typically for the last step before bottling.
Some wineries prefer not use membrane, and that is ok also. One has to make sure re-fermentation does not occur in the bottle, whether by filtering with a finer rated micron cartridge, or though additives.
Beverage Membranes provide the best assurance before bottling but must be properly prefiltered to avoid pre-mature plugging. If pre-filtration is sufficient, the membrane is designed to capture the stray organisms that may pass through a nominally rated filter and provide for a long filter life.