The Swig™ straw uses the same NASA derived filtration media as our original bottles. It purifies water using an electro-adsorption process and works against bacteria, viruses and other waterborne contaminants found in outdoor sources. The Swig™ features a fast water flow and improves water taste and odor as it filters.With a mere 1.5 ounces of weight and a compact design it allows carrying in a pack, a pouch or a jacket pocket