0.5 Cubic Foot, perfect for portable water softeners needing resin media replacement. 100% compatible replacement for any water softener system using 0.5 Cubic Feet of media with 16,000 grains capacity. iFilters cation resin provides a high purity, premium cation resin designed for the treatment of foods, beverages, potable waters, and water used in the processing of food. This high-grade resin complies with the U.S. Food & Drug Administration (USFDA) for use in the treatment of foods for human consumption. Specifications: Screen Size Range - US Standard Screen: 16 - 50 mesh, wet. Particle Size Range: +1.2 mm less than 5%, -0.3 mm less than 1%. Moisture Retention, Na+ form: 46 - 50%. Swelling Na+ greater than H+: 8 - 10%. Specific Gravity, Moist Na+ Form: 1.27. Total Exchange Capacity, Na+ Form (Wet, volumetric: 1.9 eq/l min.) (Dry, weight: 4.5 eq/kg min.). Operating Temperature, Na+ Form: 248°F (120°C). pH Range Stability, Na+ Form: 0 - 14. pH Range Operating, Na+ Form: 6 - 10. 100% compatible with the following systems: iFilters Water Softeners: WS-P-1017. On The Go: OTG4-StdSoft, OTG4-DBLSOFT & OTG4-PSOFT. ABCWaters: PWS16. Flow-Pur 10,000 M7002 (Requires 0.33 CuFt). And any other brand water softener needing high quality resin media. This package of 0.25 CuFt media offers 8,000 grains capacity. Some portable systems require 8,000, 16,000 or 32,000 grains capacity. Systems with 32,000 grains capacity need a full 1 CuFt of media.