Type I Pool Filter CartridgeType 1 pool filter replacement cartridge is a part of your routine maintenance for your swimming pool or hot tub cleaning. Inner diameter: 1.1 inches.Outer diameter: 3.1 inches; Total height: 3.5 inches. Filter Cartridge (For bestway size 1 filter) features ultra fine heavy-duty paper with more pleats for better filtration. Premium QualityFor bestway pool filter type 1 elements are made unique trilobal filtration fabric structure, durable and practical dacron material which could make the filter cartridge achieve reusable.The pool filter core is easy to adjust, easy to replace regularly, keeps the pipes clean and provides you with safe and healthy water from the pool. Powerful Filtration PerformanceThis massage pool filter type I element could make sure the water is clean and fresh. Helps Pool to get rid of build-up and debris by collecting pool gunk! This filter cartridge efficiently removes hair, leaves, dust, sediment, sand, etc. Easy to CleanThe filter cleans easily. Simply remove the filter from the pump and spray the dirt with a garden hose. Be careful not to wipe with force or use a high-pressure water stream as this will damage the filter paper. MaintenanceThe filter element is suitable for 300/330 gallons per hour to ensure that the filter pump works more efficiently. It is recommended to replace the filter element every two to three weeks to keep your pool or lay-z-spa clean.