Zn-IX ion exchange pillows are specially formulated with food-grade ion-exchange media, suitable for downspout and catch basin treatment. The 4-liter pillow is capable of absorbing up to 250,000 milligrams of dissolved zinc. Cationic DVB-based exchange resins work like water softeners, and can be regenerated using 10% salt water and rinsing. (Check with state and local regulations before regenerating StormwaterSupply resin systems. Contact us for more information.) Price is PER PAIR of Pillows.