The Costguard CGS-55 is a 20-Inch low profile Slim-Line triple bowl housing in Series/Parallel configuration which uses 1 sediment Prefilter and 2 carbon filters of the same type. Costguard's CGS-55 system is manufactured of durable polypropylene and has excellent chemical resistance. The Costguard CGS-55 Triple Housing System includes water pressure gauge, wall mounting bracket and hardware for fast, easy installation. The CGS-55 is also equipped with a pressure relief button to relieve water pressure during cartridge changes. CGS-55 System is shipped fully assembled. Cartridges sold separately. Choose the appropriate 20-inch cartridges for your needs. Use the first bowl for prefiltration in series with two parallel carbon cartridges of the same type. Choose from several options listed below. The Costguard CGS-55 Bowl housing assembly accepts drop in cartridges of standard size that fit most 20-inch Slim-Line design systems. Everpure part number DEV9100-50 or DEV910050.