(1) Color-changing deionzation filter cartridge;
(2) Refillable & reusable filter cartridge,save on refills and buy just the media;
(3) Clear cartridge allows easy detection when color-changing mixed bed resin is exhausted.
(4) Change color from dark blue to green and from green to yellow as resins exhaust;
(5) Ideal for making high quality pure water after RO system for household,saltwater,aquariums,ect;
(6) 10"/20" standard size clear cartridge,fits all standard 10"/20" conister housings.