The Billi water filter cartridge 994051 will Remove/Reduce Dirt, Rust, Sediment Particles, Chemicals, Chlorine. 5 Micron Triple Action Filter with Scale Inhibitor to help stop the scale build-up and protect elements and boilers. The Billi water filter cartridge 994001 filters now replaces many of the older Billi swing change filters including the twin filter sets. This Filter also replaces Q10-C OR 990412 5 MICRON FILTER