GENUINE Enolmatic / Enolmaster Filter Cartridge - 0.45 (0.5) Micron - Cartridges are made of food-grade material and are washable and reusable. There is no danger of the material separating from the filter and entering your wine. The level of filtration varies considerably among winemakers. Generally though, a 5 or 1 micron is sufficient for reds, and either 1 micron or 0.45 micron for whites. Generally speaking the sweeter or clearer the wine, the finer the filtration cartridge is needed. The 0.45 micron removes yeast cells but not color or flavor molecules. It will not remove bacteria so keep up on your sanitation. IMPORTANT: Cartridges of different micron size look exactly the same, so mark the filter cartridge when first removed from the box. One filter cartridge per filter housing is required for filtering. Choose you micron from the drop down menu.