Portable purification system is built right in to your water bottle * Energy efficient design last 10,000 cycles, even with exposure to cold weather. * Impact and weather resistant cap insulates UV bulb for effective purification every time. * Clear LCD readouts make water treatment simple and intuitive. * Fill from tap,streams,spigots,and more. Reduces bacteria-99.9999%,viruses-99.99%,protozoa-99.9%