Annual Replacement Set for 5 Stage Undersink Reverse Osmosis includes 3 prefilter cartridges, standard size 75 GPD (Gallons Per Day) Reverse Osmosis membrane, and Coconut Carbon USA Made inline post filter. Total filters: 5 pcs 1st Stage. 5 Micron High-Quality Sediment Filter Cartridge, 10″x2.5″. Removes dirt, silt, sand, rust, and scale particles. 2nd Stage. GAC Granular Activated Carbon filter cartridge, Size: 9 3/4″ x 2.5″. Effectively reduce unwanted tastes and odor and also chlorine taste and odor. Removes chlorine, chloramine, VOCs and etc. 3rd Stage. Carbon Block filter cartridge, Size: 9 3/4″ x 2.5″. Reduces Chlorine, Chloramine, VOCs. Improves taste and odor. 4th Stage. 75 Gallons Per Day (GPD) Reverse Osmosis Membrane, type 1812-75 5th Stage. 10″x2″ Inline Omnipure (USA) T33 Post Coconut Carbon filter cartridge. Improves taste and odor.,1/4″ FPT. SKU#: CL10ROT33-B 2 Quick Connect Elbows (1/4" x 1/4") included.