You won't believe the power of this ultra filtration membrane cartridge – its pore size of 0.01 microns can remove 99.99% of hazardous bacteria, all without any chemicals! Connect it to a water bag or bottle (not included) and enjoy the 11.8” (30cm) of total length. Designed with a back flush feature, just blow air through the water straw after drinking to keep it clean and preventing any clogging.