Complete Filtration Services 10"x2.5" Refillable DI De-Ionization Filter RO/Aquarium Re-fillable DI filter for RO DI system with Nuclear grade color changing di resin 2.5" x 10" with 1/4" ports for easy installation This high grade DI resin, with color indicator (changes from blue/green to brown) to identify when the resin is exhausted. Great for reducing TDS in reverse osmosis systems Compare to AquaticLife Color Changing Mixed Bed Resin DI Cartridge for RO Buddie Reverse Osmosis System and save