Amazon offers Prime members the LifeStraw Personal Water Filter for $14.99 with free shipping. That's around $5 under the lowest price we could find via third-party sellers, although we saw it for a buck less in December. This award-winning, BPA-free device enables you to safely drink contaminated water. It removes almost 100% of waterborne bacteria and protozoan parasites and will filter up to 1,000 liters of water.