Compatible to Intelifil (IF-SM-WS020B) 20"x4.5" 84,000 mg-L Water Softening Filter by IPW industriesIPW Industries Compatible with Intelifil 20" x 4. 5" 84,000 Grain Water Softening Filter Cation resin cartridge for whole house scale prevention in standard Big Blue housings Removes calcium and magnesium Prevents scale buildup 84,000 mg L capacity Fits standard 20" housings This softening resin cartridge uses dark cation bead technology to remove dissolved hardness minerals that cause scale in pipes, appliances, and fixtures. Built to the IF SM