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. 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. *Note: Filter life may vary based on local water conditions or use patterns.