Haws Hawsclean Portable Eyewash Cleansing Stick is a self-contained­ cartridge effectively prevents the growth of algae, fungi, Legionella, E-Coli and other harmful bacteria in most portable gravity-fed or pressurized emergency eyewash equipment without the use of power or chemicals. Simply immerse the stick in your tank for immediate protection: Copper-Silver Ionization Technology keeps water safe and clean without the hassle and cost of frequently replacing chemicals.