Ultraviolet Light works like this:
The ultraviolet rays attack harmful infectious microorganisms in your water, efficiently limiting their ability to reproduce.
UV systems are highly recommended to those who may suspect giardia, E. coli, cryptosporidium or other types of bacteria and viruses in their water.
Housing: reinforced polypropylene; Filter Cartridges: 5 microns sediment filter & granular carbon activated filter; Water Chamber: stainless steel 3O4; UV lamp Rated life: 9,000 (hrs); High purity quartz tube.