Lifesaver Bottle 4000 Ultra Filtration Water Bottle Replacement Cartridge LIFESAVER technology filters out bacteria, viruses, cysts, parasites and fungi from water Filters 4,000 liters / 1,056 US gallons of water Tested by Independent Test House to meet adaption of NSF Protocol 231 FAILSAFE - an automatic indicator when the cartridge needs replacing BPA and BPS free Lifesaver replacement cartridge 4000 liter Replace when bottle stops working