The compact PTG-520 Carbon Filtration System are available to the owner's of portable RO systems as a new option. The PTG-520 system features a lighter design, lower profile and is cost effective. The filter has been tested in order to meet specific regulations related to the use of carbon as detailed in ANSI/AMMI/ISO 23500, specifically Annex F & G. The design includes 2 carbon block filters in series and is engineered and manufactured with clean design.