CBTAD Replacement Water Filter Cartridge for the Water Guardian Countertop The Best Performing Solid Carbon Block Filter Filter Certified by NSF for standards 42 & 53 Reduces a wide range of contaminants including Cysts, Lead, PCBs, MTBE, Mercury, Asbestos, Chloramine, VOCs and many more Filter life/capacity is approximately 750 gallons 30 day money back guarantee - Filter Lasts 1 year