100% Cation Resin: 10 inch x 2.5 inch Cation Resin Water Softener filter is invented with a sodium based, non-solvent rinsed softening resin to reduce hardness, minerals and scale deposits in low flow rate applications, Utilizes a bed of sodium form cation resin beads for reduced hardness and scale deposits with a Cartridge capacity dimensions - ID: 30mm OD: 70mm. ION EXCHANGE: 10" x 2.5" Cation Resin Water Filter uses ion resin to reduce the Calcium, Magnesium, and Iron in tap water, a prefect way to soften the water before your coffee machine or washing machine, protecting your appliances from building scales & reduces the chance of damage for appliances. Life span of 6-12 months (depending upon water quality). Universal Size: The standard size of 10 inch x 2.5 inch was designed fits AF-10-3003, WS-10, UDF-10C100E, 155319-43 and can replace any 10" x 2.5" water softener cartridge. 3 Step Easy installation, Twist to open the housing cap replace the filter and twist again to close the housing cap. Customer Note: Max Water recommends the cation filter to be used as a mid stage between Sediment (pre filter) & CTO (post filter) to increase filter life cycle and taste. Why Max Water - We have 15+ years of experience in water filtration industry providing solutions with a smile to millions of families. Make Max Water your solution to all your filtration needs. (1) Calcium, Magnesium TDS Hardness Reduction Water Softening Cation Resin Filters Compatible with 10" Standard Whole House Water Filter Systems