ULTIMATE FILTRATION: Field cleanable ceramic cartridge with .0002 mm pores removes bacteria (99.9999% Klebsiella terrigena) and protozoan cysts (99.9% Giardia and Cryptosporidium). Suitable for long-term extreme use in clear, turbid, or silty water. SWISS QUALITY & DURABILITY- 20-YEAR GUARANTEE. This steel bomb-proof filter is trusted by military and emergency professionals around the world to deliver water free of bacteria and protozoa. RELIABLE HIGH OUTPUT: Generates up to 1 liter of filtered drinking water per minute. Suitable for 1 to 4 people. PORTABLE & VERSATILE DESIGN: The easy-to-use and compact 20 oz (550 g) design -- with an ergonomic pump handle -- makes this filter ideal for hiking, backpacking, group camping, and emergency preparedness. EASY TO CLEAN IN THE FIELD: Simply rinse the prefilter to remove any particles and brush the ceramic element with the supplied cleaning pad until the original filter color returns. Filter up to 13,000 gallons (50,000L) before replacing the filter. Rugged, durable construction for extreme conditions The 0.2 micron silver-impregnated ceramic filter passes EPA rigorous testing for removal of bacteria & protozoan cysts Highest quality construction - Lifetime warranty against materials & workmanship Included Universal Bottle Clip makes filling all type bottles easy Included measuring gauge and cleaning pad for field maintainability