Filter Replacement for Oko Assorted Colors - Level 1 Manufacture ID: OKO-RFL1 Uses positively charged electro-absorptive particles to attract and hold water contaminants like a sponge. Filter cartridge includes a patent-pending Upstream™ hygienic system to ensure each sip is a fresh one. Uses FDA compliant components and meets or exceeds NSF42 standards for reduction of chlorine. Not for use with hot water tea coffee sweet or sour beverages. For use with generally safe and regularly monitored municipal water in cities and rural areas.