NDuR Advanced Replacement Filter for our 28oz 38oz 46oz bottles and water pump is the most laboratory and field-tested of their kind in the world using EPA protocols and tested to NSF/ANSI Standards 42 and 53 by Broward Testing Laboratory. Each contains an Advanced Filter that uses the advanced technology of Seychelle. NDuR s Advanced Filtered products remove what most other filters cannot; eliminating up to 99.9% of Micro-Organisms such as Giardia and Cryptosporidium up to 99.99% of all chemicals and heavy metals as well as up to 99.9999% of viruses and bacteria including E-Coli found in water sources. The replacement filter can filter up to 100 gallons of water or more depending on the quality of the source water. Seen as one of the safest most convenient low-cost alternative to boiling purification drops and bottled water and is suitable for travel throughout the world.