You add the cartridges you want in the system!
Product Description
20" 3-Stage Big Blue Filter Assembly (3 housings connected together and attached to the mounting bracket). The bracket is coated steel plate and the inlet/outlet is 1 inch.
Cartridges and end fittings are not included in this specific assembly.
You may want to use the following cartridges:
First Stage: Sediment Cartridge 4.5"x20". You can use a 25-micron
melt blown sediment cartridge in this canister (e.g., SF-BB-2025).
Second Stage: Granular Activated Carbon Cartridge 4.5"x20"(e.g., GACBB10) or use a Specialty Cartridge to treat unique water quality issues (e.g., water softener cartridge, mixed Bed Deionization Cartridge, iron removal cartridge).
Third Stage: Carbon Block (e.g., 91151N) Cartridge 4.5"x20" or GAC (e.g., GACBB10) if stage 2 has specialty cartridge.
Inlet/outlet: 1" Female Threads.
This assembly is mostly used as Whole House Filtration System or on the discharge line of a private water well. It can also be used as Point of Entry(POE) device in any application.