Advanced Filtration: Traps impurities and contaminants with its .35 micron pleated mesh design Easy Installation: Compatible with Big Blue water purifiers for hassle-free replacement Durable & Reusable: Built to last with a robust mesh material, ready for multiple uses Improved Water Quality: Removes unwanted particles for cleaner, fresher drinking water Space-Saving Design: Compact 20" size fits perfectly in water pitchers and purifiers Nelsen pleated Big Blue style filter cartridge. Reusable pleated .35 micron filter.