Removes ionic contaminants to achieve specified water quality. Fits models: OPT030PLXX11503-1 , OPT030XXXX11503-1 , OPT060PLXX11503-1 , OPT060XXXX11503-1 , MED030XXXX11503-1 , MED060XXXX11503-1 , MED100XXXX11503-1 , MR030XXM1-115 , MR060XXM1-115 , MR100XXM1-115