The Costguard CGS-23 is a 20-inch low profile Slim-Line dual bowl housing in Parallel configuration, requiring use of 2 of the same filters. Costguard's CGS-23 dual housing system is manufactured of durable polypropylene and has excellent chemical resistance. The Costguard CGS23 is a 20-inch low profile Slim-Line dual bowl housing system. The Costguard CGS-23 Dual Housing System includes water pressure gauge, wall mounting bracket and hardware for fast, easy installation. The CGS-23 is also equipped with a pressure relief button to relieve water pressure during cartridge changes. CGS-23 System is shipped fully assembled. Cartridges sold separately. Choose the appropriate 20-inch cartridges for your needs. Always install two cartridges of the same type. Choose from several options listed below. The Costguard CGS23 Bowl housing assembly accepts drop-in cartridges of standard size that fit most 20-inch Slim-Line design systems. Everpure part number DEV9100-23 or DEV910023.