USWF-8P-12LBS is one quarter cubic foot of premium 8% cross-linked water softener replacement resin. This resin can be used with any water softener system from traditional mechanical softeners, new digital water softeners, or even portable RV systems. This strong acid cation exchange resin supplied in the sodium form is extremely robust and has excellent physical and chemical characteristics. Are you regenerating your water softener more often to keep water soft? Is your water softener going through more salt than it used to? Is your water no longer lathering well with soaps or leaving scum in your tub? Chlorine found in municipal city water supplies degrades water softener resin over time causing it to deteriorate and loose effectiveness. Give new life to your water softener with USWF-8P water softener resin.