This High Quality 3 set SmartPack RO Reverse Osmosis Replacement filter cartridges (Pre-filters) are NSF Certified measuring 2.5" x 10". These filters fit any standard 4 or 5 stage RO System or Drinking Water System. Reduces chlorine taste and odor. Reduces fine particles like sediment, sand, silt, soil and rust. Expected life span 4 - 6 months or 3000 gallons*. Includes: (1) 2.5" x 10" high quality 5 micron sediment filters and (2) 2.5" x 10" 5 micron carbon block filters. Specifications: High-quality replacement water filters Carbon Blocks made from High Purity NSF Certified Coconut Carbon - Compatible with all standard 4 or 5 stage RO and filtration systems - NSF Certified - Compatible RO system: APEC, US Water RO Systems, US Water Galaxy, US Water Aquapurion, Watts Premier systems, Purevalue, Proline Plus, Proline Gold, Nelson, Isopure, iSpring, Tier1, Hydronix, Max Water Systems, AQUARIUM, Titan Water Pro, Home Pure, Premier Water System, Blue Wave, Water COP, Reefkeeper, Typhoon and all standard 4 - 5 stage RO Systems. Also Compatible With: ROES-50, 5EZ50, GTS-550S, NRO05-50, 200-GX-5050, ISO-RO5, GTS-550, Tier1, RO5-WF, RO550-W, W-525, WP5-50, WP-5, 5SV, RCC7, RCW7, RCW5, RCC7P, RCC1P, RCB4T, RCC7U, RCC7AK, And Many More. Comparable to: APEC FILTER-SET-ES, iSpring F3 and F6CTO, Watts Premier 560002. *Note: Filter life may vary based on local water conditions or use patterns.