Product Name: 10 Inch-40 Inch Wound Filter for Domestic RO Water Purifier Model NO.: 10" 20" 30" 40" Cartridge Installation: Vertical Lifting Filtration Grade: Medium Filter Usage: Liquid Filter Type: Pocket Filter Filter Bag Filter: The Filter Type Cartridge Filter: Wood Pulp Fiber Filter Medium Material: Cotton Material: Polyester 10 Inches: 20 Inches Trademark: HP OEM Transport Package: Neutral(Blank) Specification: CE Origin: China HS Code: 84219910 Product Description Length10" 20" 30" 40"materialcottonID28mmOur string wound filter cartridges are structured loose outer layers and tight inner layers which can offer true depth filtration for high dirt holding capacity and extremely low media migration to ensure temperature and chemical compatibility.The main advantage of the string wound filter cartridge is its exceptionally high structural strength, therefore, they can withstand severe operating conditions.