2 Pack Replacement Inline Deionization (DI) Canisters for Universal RO/DI Systems - 1/4" Inlets | Engineered for Zero TDS Ultrapure liquid | Easy Filter Change

The cation component is a strong acid sulfonated polystyrene gel type cation exchange resin.. Mixed Bed DI Color Changing Filter In Clear Housing.The anion resin is a Type I strongly basic gel resin with an indicator dye that changes from blue to brown as the resin exhausts. ONLY USE AFTER PROPER REVERSE OSMOSIS PRE-TREATMENT This particular green resin is extremely high high-grade resin compared to the average blue resin. 1 year Satisfaction Guarantee, w/ life time support by aqua technology experts based in California. This product is excellent for aquariums, laboratory testing, and other applications where ultra-pure aqua is necessary