The Sawyer Squeeze Filter consists of a filter with a push/pull cap that attaches to one of three different sized reusable pouches, 12, 16, or 32oz, or most threaded plastic bottles. The system is lightweight, weighing only 3oz., and is very portable. Despite its small size it removes upwards of 99.99999% of all water-found containments. The filter can even stand up to high-pressure backwashing due to Sawyer’s robust hollow-fiber membranes, although because of the filter’s large surface area this isn’t a frequently required task.
You can buy here.